AU2006252276A1 - Analytical disc with optically trackable encoded information and related optical inspection system - Google Patents

Description

\O

IN

SAnalytical Disc with Optically Trackable Encoded Information and Related Optical Inspection System 00 The present invention relates to apparatus, to a system, and to a method for OC carrying out optical analysis of samples and is applicable in particular to the analysis of biological, chemical and biochemical samples.

Many chemicals, biochemical and biological assays rely upon inducing a Cchange in the optical properties of a biological sample being tested. For example, in order to test for the presence of an antibody in a blood sample, possibly indicating a viral infection, an enzyme-linked immunosorbent assay (ELISA) can be carried out which produces a visible coloured deposit if the antibody is present. An ELISA makes use of a surface which is coated with an antigen specific to the antibody to be tested for. Upon exposure of the surface to the blood sample, antibodies in the sample bind to the antigens. Subsequent staining of the surface with specific enzyme-conjugated antibodies and reaction of the enzyme with a substrate produces a precipitate which shows up the level of antigen binding and hence allows the presence of antibodies in the sample to be identified. This identification is usually carried out using a light microscope which allows an area of the substrate to be viewed by an operator.

In addition to colour staining using an ELISA, techniques such as fluorescence and gold labelling can be used to alter the optical properties of biological antigen material. Similar techniques are also used in general histology to visualise specific areas of tissue, e.g. particular cell types or cell structures, as well as in cell culture.

A significant disadvantage of existing optical analysis techniques is that they are open to human error because of their subjective nature. These techniques are also not suited to uses where a high throughput of samples is required, for example in blood screening applications or cervical smear tests, and are thus relatively expensive to use. The cost factor is exacerbated because, more often than not, different equipment is required for each particular technique.

An object of the present invention is to provide a technique for carrying out the optical analysis of samples which overcomes or at least mitigates certain of these disadvantages.

U

d.) SIt is also an object of the present invention to provide an optical analysis 00 technique which allows high speed automatic analysis of biological, biochemical and chemical samples and which is versatile enough to allow it to be used for a variety of different studies.

These objects might be achieved by adapting the technology which has been developed in the field of audio and video compact discs to scan surfaces, to which a sample has been attached, using a light beam which is substantially focused onto that surface. A detector is arranged to detect light reflected from, or transmitted through that surface, and to determine from analysis of the detected light whether the light beam has been interfaced with by the sample material.

According to a first aspect of the invention there is provided an optical disc for use in conducting an optical inspection of a biological, chemical or biochemical sample in association with an optical reader capable of optically scanning and reading optical discs, said disc comprising: a substrate having optically readable position and tracking encoded information to be read by said reader for controlling the scanning of said reader relative said disc; and a sample support surface positioned to be scanned by said reader and on which said biological, chemical or biochemical sample may be located, for optical inspection by said reader, said sample support surface being internal to said disc.

According to a second aspect of the invention there is provided a system for conducting optical inspection of a biological, chemical or biochemical sample comprising: a disc according to the first aspect of the invention; and an optical disc reader.

According to a third aspect of the invention there is provided a method of conducting an optical inspection of a biological, chemical or biochemical sample employing an optical disc adapted to be read by an optical reader, comprising the steps of: providing a respective sample in association with said disc wherein said respective sample is internal to said disc; conducting an optical inspection of said sample using an optical reader; and reading encoded optically readable position and tracking information provided within said disc by said reader and using said information in conducting said inspection of said sample.

According to a fourth aspect of the invention there is provided an optical disc for use in conducting an optical inspection of a biological, chemical or biochemical sample in association with an optical reader capable of scanning and reading optical discs with a beam of light, said disc comprising: an optically transparent substrate having a semi-reflective layer which reflects a portion of said beam of light to form a reflected beam and transmits a portion of said beam of light to form a transmitted beam, said semi-reflective layer including optically readable encoded information to be read by said reader for controlling the scanning of said reader relative to said disc, said encoded information providing modulation of said reflected beam; and a sample support surface positioned to be scanned by said reader and on which said biological, chemical or biochemical sample may be located, for optical inspection with said transmitted beam. According to a fifth aspect of the invention there is provided a system for conducting optical inspection of a biological, chemical or biochemical sample comprising: a disc according to the fourth aspect of the invention; and an optical disc inspection assembly including: a radiation source for providing at least one beam of electromagnetic radiation; a detection system comprising one or more detectors for detecting radiation reflected from and transmitted through said semireflective layer.

According to a sixth aspect of the invention there is provided a method of conducting an optical inspection of a biological, chemical or biochemical sample employing a disc adapted to be read by an optical reader, comprising the steps of: providing such a sample associated with a disc according to the fourth aspect of the invention; conducting an optical inspection of said sample using an optical reader; and

\O

4 U reading said encoded information with said reader.

According to a seventh aspect of the invention there is provided a histological C inspection system including an optical disc for use in conducting a histological inspection of a specimen, an optical reader capable-of scanning and reading the optical disc and a computer display capable of displaying the specimen, said disc comprising: C a substrate having optically readable position and tracking encoded n information to be scanned and read by said reader for controlling the scanning of said IDreader relative said disc and specimen; and Sa specimen support surface associated with said disc in optical alignment with encoded information of said disc to be scanned by said reader, a presence of a biological specimen on said support surface being determined by an optical interference with the reading of encoded information of said disc.

According to an eighth aspect of the invention there is provided an optical disc for use in conducting a microscopic inspection of a specimen in association with an optical reader capable of optically scanning and reading optical discs, said disc comprising: a substrate having optically readable position and tracking encoded information to be read by said reader for controlling the scanning of said reader relative said disc; and a support surface positioned to be scanned by said reader; and a specimen located on said support surface for microscopic inspection by said reader.

According to a ninth aspect of the invention there is provided a system for conducting a histological inspection of a specimen comprising: an optical disc for use in conducting a histological inspection of a specimen, in association with an optical reader capable of scanning and reading the optical disc and a computer display capable of displaying the specimen, said disc comprising: a substrate having optically readable position and tracking encoded information to be scanned and read by said reader for controlling the scanning of said reader relative said disc and specimen; and a specimen support surface associated with said disc to be scanned by said reader, said support surface being provided to receive a biological

\O

aspecimen located on said support surface for histological inspection by said reader and display on said computer display; and 00 a histological inspection system adapted to read information stored on said disc and discern attributes of said specimen.

According to a tenth aspect of the invention there is provided a method of conducting a histological inspection of a specimen in association with an optical disc and optical reader including; IND providing a specimen support surface on or within said disc; providing optically readable position and tracking information to be read by said optical reader encoded on or within said disc; using a light source and laser generator in said reader and varying the resolution of said reader for microscopic inspection of a specimen on said surface using optical magnification between said source and said generator.

According to an eleventh aspect of the invention there is provided a method of conducting a histological inspection of a specimen in association with an optical disc and optical reader, said method comprising providing a specimen support surface on or within said disc; providing optically readable position and tracking encoded information to be read by said optical reader in association with said disc; reading said encoded information with an optical reader and visually inspecting said disc for a specimen using a light source and detector of said reader or another reader; and displaying said specimen on a computer display using said position and tracking encoded information to locate said specimen to be displayed.

According to a twelvth aspect of the invention there is provided a method for carrying out a histological analysis in association with a computer display unit, comprising: providing optically readable position encoded information in conjunction with an optical disc capable of being scanned and read by an optical reader, providing a biological specimen for histological inspection on a sample support surface associated with said optical disc; Svisually inspecting said specimen with a light source and detector system and producing a first data stream suitable for input to a computer 00 display unit to display said specimen on said display unit; and optically reading the encoded information of said disc and producing a IN 5 second data stream suitable for input to a computer to use said position ~information in association with the display of said specimen.

SAccording to a thirteenth aspect of the invention there is provided a IND histological inspection system including a digitally encoded optically readable disc, an Soptical reader capable of optically scanning and reading the optical disc and a computer associated display unit, said disc comprising: a substrate having encoded position and tracking information readable by said optical reader; and a support surface associated with said disc that is scanable by said optical reader, said support surface being provided to receive a tissue cell specimen located on said support surface for optical inspection by said reader so that said specimen can be displayed on said display unit.

According to a fourteenth aspect of the invention there is provided a method of conducting a histological inspection of a biological sample comprising: supporting at least one sample on a surface location of a substrate; directing electromagnetic radiation from a radiation source onto the substrate; scanning over the substrate by rotating the substrate about an axis substantially perpendicular to the substrate and by moving the radiation source in a direction having a component radial to said axis; detecting radiation reflected from and transmitted through the substrate and the sample and providing an output signal from the detected radiation corresponding to the optically inspected sample at said surface location on which said incident beam is currently directed; modulating at least a part of said incident beam by distributed electromagnetic radiation modulating means provided on the substrate at said surface location; Sanalyzing said output signal during the scanning step to extract, from said detected radiation, digital position address information at said surface location on 00 C1 which said incident beam is currently directed; converting said output signal to a digital form by an analog to digital IND 5 converter; transmitting said output signal in digital form to a bitstream generator Sand generating an output signal bitstream; IN transmitting said digital position address information to an address bitstream generator and generating an address bitstream; and transmitting said output signal bitstream and said address bitstream to a computer associated display unit and displaying said sample.

According to a fifteenth aspect of the invention there is provided apparatus for conducting a histological inspection of a biological sample supported on a substrate, the apparatus comprising: means for supporting a substrate and for rotating the substrate about an axis substantially perpendicular to the substrate; a source of electromagnetic radiation for providing an incident beam of electromagnetic radiation; drive means for moving the radiation source over the mounted sample in a direction having a component radial to said axis so that in combination with the means for rotating the substrate the incident beam can be scanned over the substrate; detector means for detecting radiation reflected from or transmitted through the substrate and sample and for providing an output signal corresponding to the detected radiation; decoding means for extracting digital address information or calibration information from said output signal, said information having been modulated by radiation modulating means provided on the substrate at the location on the surface of the substrate on which the incident beam is currently directed; and means for using said information to align the scan with the substrate and for providing a display of said sample on an associated computer display unit.

U

According to a sixteenth aspect of the invention there is provided a method of

C

conducting a histological inspection of a biological sample in association with a 00 r computer display unit, comprising: supporting at least one sample on a substrate at a surface location associated'with said substrate; Sdirecting electromagnetic radiation from a radiation source onto the t substrate; ID scanning over the substrate by rotating the substrate about an axis Ssubstantially perpendicular to the substrate and by moving the radiation source in a direction having a component radial to said axis; detecting radiation reflected from and transmitted through the substrate and the sample and providing an output signal from the detected radiation corresponding to the optically inspected sample at said surface location on which said incident beam is directed; modulating at least a part of said incident beam by distributed electromagnetic radiation modulating means provided with the substrate at a said surface location; analyzing said output signal during the scanning step to extract, from said detected radiation, digital position address information at said surface location on which said incident beam is directed; and displaying a visual representation of said sample on a display of said computer display unit generated by use of said output signal from the detected radiation corresponding to the optically inspected sample.

According to a seventeenth aspect of the invention there is provided a system for carrying out an a histological inspection of a sample the system comprising: an optical disc having a surface for supporting at least one sample; a source of electromagnetic radiation for providing an incident beam of electromagnetic radiation; means for scanning across said surface; detector means which in use is arranged to detect radiation reflected firom and passing through the substrate and the sample, the disc being provided with distributed electromagnetic radiation modulating means for modulating at least a part Sof said incident beam with a digitally encoded position address at the location on said surface on which the incident beam is currently directed, the detector means being 00 arranged to decode the modulated radiation to determine the encoded address and to determine if the incident beam radiation has been modulated by any of said material ID 5 present in the sample; and a computer display unit and means for generating digital bitstream information from information provided by said detector means to display said sample.

\According to an eighteenth aspect of the invention there is provided apparatus for conducting a histological inspection of a biological sample supported on a substrate, the apparatus comprising: means for supporting a substrate and for rotating the substrate about an axis substantially perpendicular to the substrate; a source of electromagnetic radiation for providing an incident beam of electromagnetic radiation; drive means for moving the radiation source over the mounted sample in a direction having a component radial to said axis so that in combination with the means for rotating the substrate the incident beam can be scanned over the substrate; detector means for detecting radiation reflected from or transmitted through the substrate and sample and for providing an output signal corresponding to the detected radiation; decoding means for extracting digital address information or calibration information from said output signal, said information having been modulated by radiation modulating means provided on the substrate at the location on the surface of the substrate on which the incident beam is currently directed; means for using said information to align the scan with the substrate; and means for displaying a visual representation of said address information and said sample on a computer display unit.

According to a nineteeth aspect of the invention there is provided a method of conducting a histological inspection of a biological sample, comprising: supporting at least one sample on a respective surface location of a substrate; Udirecting electromagnetic radiation from a radiation source onto the substrate; scanning over the substrate by rotating the substrate about an axis 00 C substantially perpendicular to the substrate and by moving the radiation source in a direction having a component radial to said axis; IN 5 detecting radiation reflected from and transmitted through the substrate and the sample and providing an output signal from the detected radiation Scorresponding to the optically inspected sample at said surface location on which said

N

D incident beam is currently directed; modulating at least a part of said incident beam by distributed electromagnetic radiation modulating means provided on the substrate at said surface location; analyzing a modulated part of said incident beam during the scanning step to extract digital position address information at said respective surface location; converting said output signal to a digital form by an analog to digital converter; transmitting said output signal in digital form to a bitstream generator and generating an output signal bitstream; transmitting said digital position address information to an address bitstream generator and generating an address bitstream; and transmitting said output signal bitstream and said address bitstream to a computer associated display unit and displaying said sample.

The present invention enables the rapid scanning of a surface coated with components from a sample to determine their presence and also if necessary their optical properties. The system is particularly suited for carrying out the automatic inspection of samples with a high throughput. Moreover, provisions of address information in or on the substrate enables the precise position of the electromagnetic radiation beam on the surface to be determined which in turn allows the accurate mapping of optical data, corresponding to attached material, to the surface. This enables regions of interest on the surface to be easily and quickly re-located.

The present invention is suited to carrying out ELISA where the specific antigen is coated onto the surface of the substrate. The surface is then exposed to the analyte and subsequently the specific enzyme and the resulting sample scanned to 0 11

NO

0 detect and quantify the enzyme linked to the surface. The system is also suited to carrying out histological analysis and to the quantitative study of gels run using 00 electrophoresis.

In a preferred embodiment of the present invention control means is arranged IsO 5 to determine the difference between the output signals provided by first and second Cdetectors, which are representative of signals detected, for the purpose of detecting a tt material without signal artifacts arising from, for example, dirt present on the side of \O the substrate opposite the support surface. The substrate may be provided with distributed address means for modulating a light beam with digitally encoded position information indicative of an area currently being scanned by the light beam, one or other of the detectors being arranged to decode the received light signal to determine the address of the location on which the light beam is incident.

Preferably, said electromagnetic radiation is visible light although infra-red or ultra-violet radiation may be suitable.

Preferably, the disc comprises a lower layer of transparent plastic on the surface of which is impressed, or otherwise produced, said digital information. This surface is coated with a partially reflective layer, for example of aluminium, which in turn may be covered by a further layer of transparent plastic.

In an embodiment of the invention the upper surface of the disc is provided with a 3D surface topology arranged to provide growth and attachment cues for cells grown on the surface. For example, the surface may be provided with a rectangular grating for causing cells to align in a chosen direction. Alternatively, growth and attachment cues may be provided by chemical patterning of the surface, e.g. using fibronectin, produced, for example, using photolithography.

In another embodiment of the present invention the upper surface of the disc is coated with a gel suitable for carrying out electrophoresis on proteins, DNA etc. In order to run the gels radially, a first electrode may be provided at the centre of the disc with a second electrode being provided around the periphery of the disc. A well may be formed in the gel into which the analyte can be placed.

In order to calibrate a system embodying the present invention, the disc may be provided with a calibration track, e.g. a series of 256 grey levels. These levels may be printed onto the surface of the track using an ink jet printer.

0 In a preferred embodiment, the substrate includes a preformed calibration scale which enables calibration of said system. Preferably, the calibration scale is a series 00 C1 of graded grey regions which reflect or transmit light to varying degrees. This scale may be printed on a surface of the substrate using an ink jet printer.

IN 5 In this specification, the word "comprising" is to be understood in its "open" 1 sense, that is, in the sense of "including", and thus not limited to its "closed" sense, j that is the sense of"consisting only of'. A corresponding meaning is to be attributed N to the corresponding words "comprise", "comprised" and "comprises" wherever they may appear.

For a better understanding of the present invention and in order to show how the same may be carried into effect, embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a diagrammatic view of a first embodiment of the present invention;

ID

D 13 SFigure 2 shows a cross-sectional view of a part of 00 a disc for use with the embodiment of Figure 1, drawn to a larger scale; IO 5 Figure 3 shows a detailed diagrammatic side r- C elevational view of a second embodiment of the present CI invention; O Figures 4 to illustrate graphs of outputs from detectors D1 and D2 shown in Figure 3; Figure 5 shows a schematic diagram of a control system of the embodiment of Figure 4; Figure 6 shows a diagrammatic view of a third embodiment of the invention; and Figure 7 shows a schematic diagram of a control system of the embodiment of Figure 6.

As discussed above, it is desirable to be able to optically scan a surface to which material is-attached for the purpose of quantitative analysis of the .material, or of a sample from which the material is derived or extracted. Figure 1 illustrates in simplified form a system which enables this to be achieved. The system uses a circular disc 1 (although any other suitable shape of disc may be used) which comprises lower and upper layers of transparent plastic material 2,3 which provide the disc with smooth upper and lower surfaces. Sandwiched between the two plastic layers is a thin layer of metal 4 which provides a light reflecting surface. The plastic may be of any suitable 14 material such that the material to be optically analysed can be attached to the upper surface of. the disc in the 00 same way in which it would be attached to any conventional substrate.

If the system is used to carry out an EISA, the appropriate antibody is bound to the upper surface of ci the disc (this may require some pre-preparation of the surface). The surface is then exposed to the sample to -be tested, e.g. blood plasma, 'in order to bind an antigens in the sample to the antibodies. The surface is then washed to remove any excess, unbound, material and exposed to the appropriate enzyme-conjugated antibodies 5 which attach to the bound antibodies. The bound enzymes 5 can be visualised by reacting them with a substrate to produce a coloured Precipitate. The precirpitate presents a m ultiplicity of minute opacrue patches over the upper surface of the disc. It will be apparent that the system is equally applicable to othe'r types of assay which produce a colour, or other light interfering, change.

The disc is mounted on a rotatable shaft 6 which is driven by a drive means (not shown in figure 1) causing the disc to rotate. An optical block 7 is mounted above the disc and is movable a long a substantially linear track. The optical block 7 comprises a laser diode 8 which produces a beam of coherent light 9 which is collimated and focused on to the surface of the disc 1 by a lens arrangement 10. The optical block also, 0 comprises a detector 11 for detecting light reflected from the surface of the metal layer within the disc.

00 c- The lens arrangement 10 includes a polarising prism 12 which allows only vertically polarised light to pass

ID

therethrough and a quarter wave plate 37 which causes c- Slight to be rotated by SD In operation, the disc is rotated by the drive 0 means relative to the optical block. With the block stationary the light beam produced by the laser diodetravels around a circular track of the disc. By moving the optical block along its linear track it is possible to scan the laser beam around any selected circular track of the disc. In areas of the disc surface where no light absorbing material is present, light passes through the upper plastic layer, is reflected from the metal layer, and travels back to the optical block, through the upper plastic layer. Light entering the optical block encounters first the quarter wavelength plate-37, which rotates the light by a further 45°, and then the polarising prism which, because the polarization of the reflected light has been rotated by 1800, causes the light to be redirected at right angles towards the detector.

When the light beam is incident upon areas of the disc surface where light absorbing material is present, light is absorbed by the material, both upon entry to and exit from the upper plastic layer of the disc, and the light received by the detector 11 is substantially

ID

D 16 o reduced.

The detector 11 is coupled to a data analysis and 00 00 logging system which stores the output of the detector.

This system may store the output as a continuous D 5 analogue signal or as discrete digital samples which represents a reduced resolution image of the surface.

g Assuming the latter, the sampling rate may be varied to Sfit the data storage capacity available.

The optical, mechanical and electrical means so far described for implementing an analyte detector are substantially as conventionally used for reading data from compact discs. One such conventional system is described in the text book 'Digital Audio and Compact Disc Technology', 2nd edition, Edited by Luc Baert et al (Sony Service Centre Europe), Newnes, 1994.

The system of Figure 1 is adequate for obtaining an image of the disc surface, or a portion of that surface when the actual location of the portion itself is no significance. .However, it may be desirable to be ableto scan a selected area of the disc surface, for example where an ELISA has been carried out only in that region, or when it is desired to look again at a specific region of interest.

Conventional compact discs encode digital information in an intermediate region of the disc by producing a series of perturbations 13 bumps or pits) on the upper surface of a lower plastic layer 14 and subsequently c=ating this surface with a reflective

ID

17 0 layer-15 such as a thin layer of aluminium. The reflective layer is then covered with a layer of 00 CI transparent plastic 16 which provides protection for the .intermediate layer (Figure 2).

ID

r- 5 It is possible to use this same technique to digitally encode position information into the disc of ND Figure 1. Assuming that the position origin is at the 0 centre of.the disc, the first position on the innermost circular track or spiral can be imprinted with the position code zero (in binary representation). Position codes can be imprinted at discrete positions every 2 to 3gm or at any other appropriate interval) around that innermost track incrementing by one between .each position. Similarly, the codes are incremented from track to track. Alternatively, address information may be distributed according to a track/sector arrangement in the same way in which servo-codes are encoded onto magnetic floppy and hard disks.

over areas of the surface of the disc which are not covered by opaque material, light incident on the-upper surface of the disc is transmitted through the upper transparent plastic protective layer and is incident upon the reflective layer. This light is reflected from the reflective metal coating except where that coating lies over a bump which causes incident light to be dispersed and not directly reflected back to the detector. The output from the detector can therefore be demodulated to determine the address of the disc surface Swhich is currently being scanned.

Over areas of the disc surface where opaque 00 C- material causes the incident light beam to be substantially absorbed rather than reflected, no

ID

r 5 position information will be present at the output of 4 the detector. However, if the density of the opaque \O material is relatively low the gaps in the address O 'information may not be significant.

c-i In situations where address information is more critical however, a more sophisticated system can be utilised for which the optics are shown in Figure 3 and which makes use of discs having address information, digitally encoded and distributed over an intermediate layer as described above. This system also makes use of the fact.that the reflective layer can be made to transmit a significant proportion of the incident light As with the system of Figure 1, the system of the-second embodiment includes a shaft 17 on which the disc 18 is moun-ed and which causes the disc to rotate and means for moving the optics along a linear track relative to the upper surface of the disc. The -roration and displacement means are not shown in Figure 2 for simplicity.

The optical system of Figure 3 comprises a light source 19, which may be for example a semi-conductor laser or a light emitting .diode, arranged beneath the.

disc. The output beam 20 of the light source is directed up an optical axis 2a to a polarising prism (a

ID

19 beam splitter) 21 which allows only light of a given polarisation to pass, i.e. only the light received 00 directly from the laser. The transmitted light is then incident upon a first lens 22 which is arranged to focus light onto the lower surface 23 of the reflective layer Cl within the disc. A fraction of the light incident upon Sthe compact disc is transmitted through the reflective

IO

p layer and exits from the upper surface of the disc.

Any material attached to the upper surface will interfere with light exiting the disc.

Transmitted light which is not interfered with is received by a collimation lens 24, focused onto the upper surface of the disc, which directs the received light onto a partially transparent mirror 25 which in turn allows a fraction of the incident light to pass therethrough whilst causing the remainder to be reflected at right angles. Light passing directly through the partially transparent mirror is incident upon a further lens 26 which focuses the light onto the detection surface of a detector D2. Light reflected at right angles by the mirror 25 is incident upon a lens 27 which focuses light onto a detector D3.

As already described, a fraction of the light incident on the reflective layer within the disc is reflected back towards the first lens 22 which acts as a collimation lens directing light back to the polarising prism 21. The reflected light is now horizontally polarised and is reflected from the polarising prism at

\D

M right angles to the optical axis. This reflected light Q is received by a fourth lens 28 which focuses received 00 light onto a detector D1.

Light reflected by the reflective layer will be

ID

modulated with the information digitally encoded into the disc so that the output from the detector Di will be similarly modulated. As this light does not exit from the upper surface of the disc it will not be interfered with by material attached to the upper sample support surface of the disc and address information can be determined from the output of D1 with minimal error.

Although not shown in Figure 2, the optical block situated below the disc also incorporates tracking optics which enables the correct tracking of the disc tracks in a similar way to that used in conventional compact..disc players. The tracking optics comprise a diffraction grating which splits the output from the laser into three parallel beams which are subsequently focused by the first lens to provide three slightly spaced-apart spots. The spacing between these spots is such that when the central spot is directly over the centre of one track the other two spots lie on either side of .that track. The detector D1 actually comprises three adjacent detectors which receive reflected light and the spacing of which is equivalent to that between the beam spots In order to align the laser correctly, the laser position is adjusted until the output from the centre detector is a maximum and the outputs from the NO 21 two side detectors is a minimum. A feedback control

U

system is used to maintain the correct tracking.

00 The output provided by detector D2 is modulated with the digital address information encoded onto the D 5 disc and, provided that no light absorbing material is C- attached to the upper surface of the disc, is substantially of the form of the output of detector Dl, i.e. the ratio of the output signals of D1 and D2 will be constant. However, if light absorbing material is io present on the upper surface of the disc this will interfere with light transmitted through the reflective layer and the output from detector D2 will drop whilst that from D1 will remain constant. The ratio of the output signals of Dl and D2 will change accordingly. If the material attached to the surface of the disc is reflective, e.g. gold labelled, the output of .Dl will rise whilst that of D2 will fall when the light beam scans the material. The ratio of D1 to D2 will indicate the presence of such material.

Figure 4 illustrates the case where the bound material is absorbent but not reflective and shows at a cross-section taken through typical disc to the surface of which a stained cell 29 is attached. The reflective layer beneath the support surface is encoded with the digital address 10101. As the beam scans along the track the ratio between the output signals of detectors Dl and D2 (Fig. 4B) remains constant where the upper surface is not covered by the cell. In the 8 central area, however, where the cell is shown covering Sthe upper surface, the signal produced by detector D2 00 C- falls so that the ratio (Fig. 4c) of the signals produced by 01 and D2 similarly drops.

ID

r 5 Figure 5 shows a block diagram of a system for ci i^ controlling the embodiment of Figure 3 with the flow of c- ND data through the system being indicated by arrows. The O analogue outputs from detectors. Dl and D2 are received by an integrated circuit 30 which determines the ratio of the two outputs. This ratio is then converted to digital form by an analogue to digital converter 31 and transmitted to a bitstream generator 34 for compression using bitstream modulation. The output from detector D1, which represents the digitally encoded address information, is also transmitted to an address bitstream generator 33 for compression. The two channel bitstream data is received by a bitstream merge and display unit which processes the data for storage and for display.

In order.to provide a more stringent measure of the variations in the intensity of light transmitted through the disc the detector D3 is provided (although this isoptional) which receives light from the partially transparent zirror through an aperture 34, lens 27 and pinhole arrangement 35. This arrangement effectively reduces the area of the disc surface from which light is received by the detector D3 and also reduces the depth of focus. If the output of detector D2, or the ratio D1:D2, exceeds a predetermined threshold the output of 0 detector D3 can be used to increase the resolution with 00 which the surface of the disc is viewed. The use of detectors D2 and D3 in combination prevents the IND lelikelihood of the detector D3 producing errors if the Cl 5 system used only detector D3. D3 may alternatively i provide a second type of detector for detecting for I example fluorescent light emitted by material attached C to the surface of the disc.

Figure 6 shows a further embodiment of the invention in which absolute position information can be determined, although the accuracy of this information may be somewhat less than that provided by the embodiment of Figures 4 and 5. However, the disc construction is considerably simplified.

The optical inspection system has a shaped arm 36 with a light source 37 and a detector 38 attached to the upper and lower ends of the arm respectively. The source and detector are connected to a laser controller 39 and a buffer 40, the latter being arranged to transfer detected signal data to a personal computer 41 via an analogue to digital converter 42 and a data store 43.

The disc 44 upon which the sample to be inspected is attached or supported is mounted on a rotatable spindle 45 which lies parallel to the bight 46 of the arm 36. The spindle 45 is driven be a spindle motor 47.

The optical axes of the light source 37 and detector 38 are-aligned with one another along the axis A-A.

ID

C 24 C The arm 36 is coupled to a stepper motor 48 which 4) precisely rotates the arm in a plane parallel to the 00 plane of the disc 44 such that, in combination, rotation of the arm and of the disc allows the light ND 5 source/detector arrangement to be scanned across the C entire useable surface of the disc. The stepper motor 48 is controlled by a motion controller 49, which in Sturn is. controlled by the computer 41, such that the CI relative position of the spindle 45 can be determined-to within an accuracy of 6m.

The disc is of a completely transparent material but is provided with a black bar 50 around a portion'of its upper peripheral surface. The bar 50 acts as an angular-calibration marking for the inspection system.

When it is required to inspect a disc, the arm 36 is moved to an outermost "home" position, where the light source/detector arrangement is situated off the disc 44.

In this position, the laser and detector are calibrated to ensure a constant, maximum, output signal. The arm 36 is then rotated to move the light source/detector arrangement towards the disc.

When the edge of the disc is detected, the arm is held stationary until the calibration marking interrupts the beam. The leading edge of the marking provides an origin to which the angular position of the detector can be referenced whilst the edge of the disc provides an origin for the radial position. Due to the accuracy of the stepper motor 48 and the spindle motcr ID C- 46, it is then possible to precisely determine the

O

position of the light source/detector arrangement 00 relative to the disc.

In the system of Figure 6, the disc 44 comprises a D 5- plurality of wells or indentations 51 formed in its C1 upper surface. The wells contain the sample to be C- inspected and are filled, for example, by 0 microtitration. Rather than scan the whole surface of C- the disc, the personal computer may be arranged to step the light source/detector arrangement over the disc surface from one well to another. This is enabled by the precise position information obtained from the calibration marking and the disc edge. Figure 7 shows a flow- diagram of the control process for this system.

The system of Figure 6 may be modified so that the light source 37 and the detector 38 are both arranged on the same side of the disc, with the disc being provided with a reflective coating on or beneath the surface on which the sample is supported. In this arrangement the detector detects light reflected from the reflective coating. The two main advantages of the arrangement are that the surface of the disc which does not support the sample may be safely handled, as it does not lie in the light transmission path, and that the signal to noise ratio of the optical inspection process may be increased because light will have to pass through a sample twice in travelling from the source to the detector.

It will be apparent that various modifications may INO 26 c-i be made to the above described embodiments without demarting from the scope of the invention. For 00 example, the support surface of the disc may be scanned with infra-red or ultra-violet r~diation rather than visible light. It is also possible to scan the surface Ci with radiation which excites fluorescence in material c-i attached to the surface and to use the detector (D2 or uIN D3) arrangement to detect light at the emission c-I wavelength.

It is also possible to construct the disc in such a way that the support surface is internal to the disc and is not the upper surface of the disc. This may provide the advantages that the sample is not damaged by handling and that a precise volume of sample may be analysed. To enable the system to be used for running gels to identify proteins, DNA etc), an appropriate gel may be provided on the upper surface of the disc. Electrodes for applying a potential across the gel may be formed integrally therewith or may be printed, or otherwise deposited, on the upper surface.

The electrodes may be spaced radially or circu.mferentially. Pits may be provided in the gel into which the material to be run can be placed.

Another modification to the above described embodiments involves replacing the light detector -with a photo-diode array, e.g. a CCD array. A preferred form of array is a linear array extending radially with respect to the disc. The light source would take the 27 oif orm of a laser line generator arranged to generate a.

radially extending line of light aligned with the diode 00i ar-ray. .Some. degree of optical magnification may be incorporated between the source And the generator to allow the resolution of the system to be varied- After each rotation of the disc, the Aource/detector arrangement would be stepped inwardly by the length of the laser line. The advantages of this arrangement are higher speed and higher resolution.

Claims (52)

1. 2. The optical disc according to claim 1 wherein said encoded information and said sample on said support surface are in alignment along a path of the reader for sequential inspection by said reader.
2. 3. The optical disc according to any of the preceding claims I through 2 wherein said encoded information is located in at least an intermediate layer of said disc.
3. 4. The optical disc according to any of the preceding claims 1 through 2 wherein said disc includes a biological, chemical or biochemical material attached to said sample support surface. The optical disc according to claim 4 wherein said material attached to said sample support surface is coloured, reflective or fluorescent.
4. 6. The optical disc according to claim 1 which includes a gel and electrodes for applying a potential across said gel.
5. 7. A system for conducting optical inspection of a biological, chemical or biochemical sample comprising: a disc according to any one of claims 1 through 6; and an optical disc reader configured to read information that is encoded on the disc
6. 8. A method of conducting an optical inspection of a biological, chemical or biochemical sample employing an optical disc adapted to be read by an optical reader, comprising the steps of: providing a respective sample in association with said disc wherein said respective sample is internal to said disc; -28- U ID conducting an optical inspection of said sample using an optical reader; and 00 reading encoded optically readable position and tracking information provided within said disc by said reader and using said information in conducting said inspection I of said sample. r- S9. The method of claim 8 wherein said steps of conducting an optical inspection and tV said step of reading encoded information each include the substeps of using quarter wave light I reflected from said disc as part of said conducting and reading steps. O The method of claim 8 wherein said encoded information is optically interrupted by the presence of said sample and said optical inspection of said sample is accomplished sequentially to the reading of said encoded information.
7. 11. The method of claim 8 wherein said disc is provided with a plurality of sample support surfaces upon which samples may be provided and a plurality of encoded information tracks, said step of optical inspection then including the sequential scanning of a plurality of samples and said plurality of encoded information tracks.
8. 12. An optical disc for use in conducting an optical inspection of a biological chemical or biochemical sample in association with an optical reader capable of scanning and reading optical discs with a beam of light, said disc comprising: an optically transparent substrate having a semi-reflective layer which reflects a portion of said beam of light to form a reflected beam and transmits a portion of said beam of light to form a transmitted beam, said semi-reflective layer including optically readable encoded information to be read by said reader for controlling the scanning of said reader relative to said disc, said encoded information providing modulation of said reflected beam; and a sample support surface positioned to be scanned by said reader and on which said biological, chemical or biochemical sample may be located, for optical inspection WII bilu LI2LIU111ILLCU UCVLIl.
9. 13. An optical disc according to claim 12 in which said encoded information and said sample on said support surface are in optical alignment with respect to said beam of light.
10. 14. A disc according to claim 12 in which said optically readable encoded information is in the form of a circular track or spiral track. -29- O O An optical disc according to any of the preceding claims 12 through 14 in which 00 said encoded information is located in at least an intermediate layer of said disc.
11. 16. An optical disc according to any of the preceding claims 12 through 14 in which said disc includes a biological, chemical or biochemical material attached to said sample support surface.
12. 17. An optical disc according to claim 16 in which said material attached to said IND sample support is coloured, reflective or fluorescent. O S18. An optical disc according to claim 12 which comprises a gel and electrodes for applying a potential across said gel.
13. 19. A system for conducting optical inspection of a biological, chemical or biochemical sample comprising: a disc according to claim 12; and an optical disc inspection assembly including: a radiation source for providing at least one beam of electromagnetic radiation; a detection system comprising one or more detectors for detecting radiation reflected from and transmitted through said semi-reflective layer, including radiation providing tracking information for use by the inspection assembly in tracking the beam of radiation on the disc. A system according to claim 19 in which said radiation source is located relative to said disc so that said sample support surface is located between said radiation source and said semi-reflective layer.
14. 21. A system according to claim 19 in which said radiation source is located relative to said disc so that said semi-reflective surface is located between said radiation source and said sample support surface. 22 Ymmt Vt1-11~, LOHI fC11IIL- ,ID detectors wherein one of said two detectors is located on the same side of said disc as said radiation source and the other of said two detectors is located on the side of said disc opposite said radiation source.
15. 23. A system according to claim 22 in which said detection system further comprises a third detector located on the side of said disc opposite said radiation source. O
16. 24. A system according to claim 19 in which said detection system comprises a video 00 monitor for viewing the results of said optical inspection. A system according to claim 19 in which said disc comprises a gel and electrodes for applying a potential across said gel.
17. 26. A method of conducting an optical inspection of a biological, chemical or it' biochemical sample employing a disc adapted to be read by an optical reader, comprising the steps of: providing such a sample associated with a disc according to claim 12; conducting an optical inspection of said sample using an optical reader; and reading said encoded information with said reader.
18. 27. The method of claim 26 in which said steps of conducting an optical inspection and said step of reading encoded information each include the substeps of using quarter wave light reflected from said disc as part of said conducting and reading steps.
19. 28. The method of claim 26 in which said encoded information is optically interrupted by the presence of said sample and said optical inspection of said sample is accomplished sequentially to the reading of said encoded information.
20. 29. A method according to claim 26 in which said conducting includes providing an optical image of said material. A method according to claim 26 in which said optical inspection includes directing a beam of radiation onto said sample to produce detectable radiation which is reflected from and/or transmitted through said sample.
21. 31. A method according to claim 30 in which only detectable radiation which is reflected from said disc is measured.
22. 32. A method according to claim 30 in which detectable radiation which is both reflected from and transmitted through said disc is measured. SI UU 111 Wl IU ,Il 1L UL lllll to said disc.
23. 34. A histological inspection system including an optical disc for use in conducting a histological inspection of a specimen, an optical reader capable of scanning and reading the optical disc and a computer display capable of displaying the specimen, said disc comprising: -31- U a substrate having optically readable position and tracking encoded information to oo00 be scanned and read by said reader for controlling the scanning of said reader relative said disc and specimen; and Ia specimen support surface associated with said disc in optical alignment with encoded information of said disc to be scanned by said reader, a presence of a biological specimen on said support surface being determined by an optical interference with the Ireading of encoded information of said disc. 0 An optical disc for use in conducting an inspection of a specimen in association with an optical reader capable of optically scanning and reading optical discs, said disc comprising: a substrate having optically readable position and tracking encoded information to be read by said reader for controlling the scanning of said reader relative said disc; a support surface positioned to be scanned by said reader, said sample support surface being internal to said disc; and a specimen located on said support surface for inspection by said reader.
24. 36. A system for conducting a histological inspection of a specimen comprising: an optical disc for use in conducting a histological inspection of a specimen, in association with an optical reader capable of scanning and reading the optical disc and a computer display capable of displaying the specimen, said disc comprising: a substrate having optically readable position and tracking encoded information to be scanned and read by said reader for controlling the scanning of said reader relative said disc and specimen; a specimen support surface associated with said disc to be scanned by said reader, said support surface being provided to receive a biological specimen located on said support surface for histological inspection by said reader and display on said computer display weUrin U aid enUoUUU 1lulll atlIiUl Uii specimen on said support surface are in optical alignment to be concurrently inspected by said optical reader; and a histological inspection system adapted to read information stored on said disc and discern attributes of said specimen.
25. 37. (Canceled) -32- O
26. 38. A system according to claim 36 wherein said encoded information is located in at 00 least an intermediate layer of said disc.
27. 39. The system according to claim 36 wherein said histological inspection system IN comprises: San optical disc reader for obtaining data from optical inspection of said specimen; it' and a computer display unit for displaying data obtained from said optical inspection of said specimen and using said encoded information. A method of conducting a histological inspection of a specimen in association with an optical disc and optical reader including: providing a specimen support surface on or within said disc; providing optically readable position and tracking information to be read by said optical reader encoded on or within said disc; and using a light source and laser generator in said reader and varying the resolution of said reader for inspection of a specimen on said surface using optical magnification between said source and said generator.
28. 41. A method of conducting a histological inspection of a specimen in association with an optical disc and optical reader, said method comprising: providing a specimen support surface within said disc; providing optically readable position and tracking encoded information to be read by said optical reader in association with said disc; reading said encoded information with an optical reader and inspecting said disc for a specimen using a light source and detector of said reader or another reader; and displaying said specimen on a computer display using said position and tracking encoded information to locate said specimen to be displayed. 1.2T mtlvuf 1 Carry ing out a hIISEQl ,aI l gl 1iayIII S1O.iU1...' wi Vhcom a u crI display unit, comprising: providing optically readable position encoded information in conjunction with an optical disc capable of being scanned and read by an optical reader; providing a biological specimen for histological inspection on a sample support surface located internal to said optical disc; -33- O o IND inspecting said specimen with a light source and detector system and pro Cn1ig a 00 first data stream suitable for input to a computer display unit to display said spec ncn on said display unit; and Soptically reading the encoded information of said disc and producing a second data stream suitable for input to a computer to use said position information in t association with the display of said specimen. I43. The method of claim 42 including the further steps of encoding tracking information on said disc so that said optical reader may track therealong.
29. 44. A histological inspection system including a digitally encoded optically readable disc, an optical reader capable of optically scanning and reading the optical disc and a computer associated display unit, said disc comprising: a substrate having encoded position and tracking information readable by said optical reader; and a support surface located internal to said disc that is scannable by said optical reader, said support surface being provided to receive a tissue cell specimen located on said support surface for optical inspection by said reader so that said specimen can be displayed on said display unit. A method of conducting a histological inspection of a biological sample comprising: supporting at least one sample on a surface location of a substrate; directing electromagnetic radiation from a radiation source onto the substrate; scanning over the substrate by rotating the substrate about an axis substantially perpendicular to the substrate and by moving the radiation source in a direction having a component radial to said axis; detecting radiation reflected from and transmitted through the substrate and the sai le 5nid provilg I anUPU ou IFuIgnlff Ire u auo oi~pn~ e optically inspected sample at said surface location on which said incident beam is currently directed; modulating at least a part of said incident beam by distributed electromagnetic radiation modulating means provided on the substrate at said surface location; -34- VO 0 0 IND Sanalyzing said output signal during the scanning step to extract, from said 00 detected radiation, digital position address information at said surface location on which said incident beam is currently directed; D converting said output signal to a digital form by an analog to digital converter; c transmitting said output signal in digital form to a bitstream generator and t generating an output signal bitstream; IDtransmitting said digital position address information to an address bitstream 0 ogenerator and generating an address bitstream; and transmitting said output signal bitstream and said address bitstream to a computer associated display unit and displaying said sample.
30. 46. The method according to claim 45, further comprising, analyzing said detected radiation during scanning to identify when said incident beam is incident upon a calibration marking, provided at a known location on the substrate, so that the scan can be aligned relative to the calibration marking.
31. 47. The method according to claim 45, wherein the electromagnetic radiation is light having a wavelength in the spectrum between ultra-violet and infra-red.
32. 48. The method according to any one of claims 45 through 47 wherein said substrate is provided as part of an optical disc.
33. 49. Apparatus for conducting a histological inspection of a biological sample supported at a location on a substrate, the apparatus comprising: means for supporting a substrate and for rotating the substrate about an axis substantially perpendicular to the substrate; a source of electromagnetic radiation for providing an incident beam of electromagnetic radiation; drive means for moving the radiation source over the mounted sample in a diiibiinhViigWacompo6n-ifT-dio-said as rnfit-iine I for rotating the substrate the incident beam can be scanned over the substrate; detector means for detecting radiation reflected from or transmitted through the substrate and sample and for providing an output signal corresponding to the detected radiation and representative of characteristics of the inspected sample at said location on which said incident beam is currently directed; decoding means for extracting digital address information or calibration O information from said output signal, said information having been modulated by distributed electromagnetic radiation modulating means provided on the substrate at the Ilocation on the surface of the substrate on which the incident beam is currently directed; and means for using said information to align the scan with the substrate and for Iproviding a display of said sample on an associated computer display unit. 0 The apparatus according to claim 49, wherein the detector means is a linear array of photodetectors.
34. 51. The apparatus according to claim 50 wherein the detector means is a linear array of photodetectors extending radially with respect to the disc.
35. 52. The substrate for use with the apparatus of any one of claims 49 to 51, comprising: means for cooperating with the supporting means to enable the substrate to be mounted and rotated; and distributed radiation modulation means for modulating at least a part of the incident beam with digitally encoded address information so that the location on the surface of the substrate on which the beam is incident is determined.
36. 53. The substrate according to claim 52, wherein the distributed electromagnetic radiation modulating means includes a sequence of spaced apart address codes.
37. 54. The substrate according to claim 52, further including a sample support surface having a three dimensional topography arranged to receive the sample. A method of conducting a histological inspection of a biological sample in association with a computer display unit, comprising: supporting at least one sample on a substrate at a surface location associated with directing electromagnetic radiation from a radiation source onto the substrate; scanning over the substrate by rotating the substrate about an axis substantially perpendicular to the substrate and by moving the radiation source in a direction having a component radial to said axis; -36- IND O Sdetecting radiation reflected from and transmitted through the substrate and the 00 samn::ie and providing an output signal from the detected radiation corresponding to the optically inspected sample at said surface location on which said incident beam is IN directed; "1 modulating at least a part of said incident beam by distributed electromagnetic t^ radiation modulating means provided with the substrate at a said surface location; \D analyzing said output signal during the scanning step to extract, from said detected radiation, digital position address information at said surface location on which said incident beam is directed; and displaying a visual representation of said sample on a display of said computer display unit generated by use of said output signal from the detected radiation corresponding to the optically inspected sample.
38. 56. The method of claim 55 further including the step of displaying a visual representation of said address information on a display of said computer display unit generated by use of said digital position address information.
39. 57. The method according to claim 56, further including analyzing said detected radiation during scanning to identify when said incident beam is incident upon a calibration marking, provided at a known location on the substrate, so that the scan can be aligned relative to the calibration marking.
40. 58. The method according to claim 56 wherein the electromagnetic radiation is light having a wave length in the spectrum between ultraviolet and infra-red and said substrate is an optical disc.
41. 59. A system for carrying out a histological inspection of a sample, the system comprising: an optical disc having a surface for supporting at least one sample; rt Il CUI electromagnetic radiation; means for scanning across said surface; detector means which in use is arranged to detect radiation reflected from and passing through the substrate and the sample, the disc being provided with distributed electromagnetic radiation modulating means for modulating at least a part of said incident -37- \O o Va IND Sbeam with a digitally encoded position address at the location on said surface on which 00 the incident beam is currently directed, the detector means being arranged to decode the modulated radiation to determine the encoded address and to determine if the incident IDbeam radiation ahs been modulated by any of said material present in the sample; and computer display unit and means for generating digital bitstream information from information provided by said detector means to display said sample. The system of claim 59 wherein said encoded address for said sample is displayed 0 on said com puter display unit.
42. 61. Apparatus for conducting a histological inspection of a biological sample supported at a location on a substrate, the apparatus comprising: means for supporting a substrate and for rotating the substrate about an axis substantially perpendicular to the substrate; a source of electromagnetic radiation for providing an incident beam of electromagnetic radiation; drive means for moving the radiation source over the mounted sample in a direction having a component radial to said axis so that in combination with the means for rotating the substrate the incident beam can be scanned over the substrate; detector means for detecting radiation reflected from or transmitted through the substrate and sample and for providing an output signal corresponding to the detected radiation and representative of characteristics of the inspected sample at said location on which said incident beam is currently directed; decoding means for extracting digital address information or calibration information from said output signal, said information having been modulated by distributed electromagnetic radiation modulating means provided on the substrate at said location; lflaiiig btU 56IIIflfdinIUII It) clllf-l L WILTI UI; DUL.ULIaL,, aIu means for displaying a visual representation of said address information and said sample on a computer display unit.
43. 62. A method of conducting a histological inspection of a biological sample, comprising: supporting at least one sample on a respective surface location of a substrate; -38- O o directing electromagnetic radiation from a radiation source onto the substrate; 00 scanning over the substrate by rotating the substrate about an axis substantially perpendicular to the substrate and by moving the radiation source in a direction having a IDcomponent radial to said axis; Sdetecting radiation reflected from and transmitted through the substrate and the t sample and providing an output signal from the detected radiation corresponding to the IDoptically inspected sample at said surface location on which said electromagnetic radiation is currently directed; modulating at least a part of said incident beam by distributed electromagnetic radiation modulating means provided on the substrate at said surface location; analyzing a modulated part of said incident beam during the scanning step to extract digital position address information at said respective surface location; converting said output signal to a digital form by an analog to digital converter; transmitting said output signal in digital form to a bitstream generator and generating an output signal bitstream; transmitting said digital position address information to an address bitstream generator and generating an address bitstream; and transmitting said output signal bitstream and said address bitstream to a computer associated display unit and displaying said sample.
44. 63. A method according to claim 62, further comprising analyzing said detected radiation during scanning to identify when said incident beam is incident upon a calibration marking, provided at a known location on the substrate, so that the scan can be aligned relative to the calibration marking.
45. 64. The method according to claim 60, wherein the electromagnetic radiation is light having a wavelength in the spectrum between ultra-violet and infra-red. is provided as part of an optical disc.
46. 66. An optical disc substantially as herein described. -39-
47. 67. A system for conducting optical inspection of a biological, chemical, or \O biochemical sample substantially as herein described.
48. 68. A method of conducting an optical inspection of a biological, chemical, Sor biochemical sample substantially as herein described. 00 (N
49. 69. A histological inspection system substantially as herein described. ,I 70. A system for conducting a histological inspection of a specimen substantially as herein described. INDI S71. A method of conducting a histological inspection of a specimen substantially as herein described.
50. 72. A method for carrying out a histological analysis substantially as herein described.
51. 73. A method of conducting a histological inspection of a biological sample substantially as herein described.
52. 74. Apparatus for conducting a histological inspection of a biological sample substantially as herein described. A system for carrying out a histological inspection of a sample substantially as herein described.