DE29918300U1 - Measuring head - Google Patents

Description

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PATENT ATTORNEY4.T&* *·· "··""" **

NG HEINER LICHTI

DlPL-PHYS. DR. RER. NAT. JOST LEMPERT D-76207 KARLSRUHE (DURLACH)

PO BOX 410760 DIPL-ING. HARTMUT LASCH TELEPHONE: (0721)9432815 FAX: (0721)9432850

04 October 1999 16888.7/99

UTILITY MODEL REGISTRATION

Applicant: Tecan Austria GmbH

Untersbergstraße la 5082 Grödig

Designation: Measuring head

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Measuring head

The invention relates to a measuring head for measuring the fluorescence and preferably the transmission of light rays, with a carrier housing, with a light source for the emission of light, preferably flash light, a measuring station with a receiving device for at least one sample container, in particular for receiving microtiter plates, and an evaluation station with a detector, preferably an electron tube with photocathode, for the evaluation of the emission signals emitted by the sample.

A fluorometer is known from the utility model AT 001406 U1, which has two opposing measuring heads. A pivoting bar is provided, which has connections for light lines that lead to the two measuring heads. The connections of each measuring head can be brought into line with a light source and a detector.

The object of the invention is to improve the detection limit of a measuring head of the type mentioned above and, above all, to increase the flexibility of the device so that it can be used in as many applications as possible.

The object according to the invention is achieved in that a beam splitter carriage which can be moved between at least two working positions is arranged in the carrier housing and in which at least two, preferably several beam splitter elements with different beam splitters for different excitation wavelengths are mounted.

In order to enable the customer to adapt the measuring head to specific applications, a preferred embodiment of the invention provides that at least one of the beam splitter elements is mounted in the beam splitter carriage in an exchangeable manner.

An embodiment of the invention is described in detail below with reference to the figures of the accompanying drawings.

Fig. 1 shows a schematic diagram of the measuring head seen from below,
Fig. 2 shows a vertical section through the measuring head,

Fig. 3 shows a side view of the entire measuring device,

Fig. 4 shows a diagram of a beam splitter carriage and an exchangeable beam splitter element and

Fig. 5 shows diagrams of the interference and polarizing filter slides.

The measuring head according to the invention has a carrier housing 1 in which or on which all parts of the measuring head belonging to the optics are arranged.

Below the carrier housing 1, a plate transporter is arranged which carries a sample container in the form of a microtiter plate which has vessels 2 (wells) for the samples 9 to be examined.

A lamp 3 for the emission of flash light is housed in the carrier housing 1, which is fed to a beam splitter element 5 within a beam path 4.

A small part of the light emitted by the lamp 3 is transmitted through the beam splitter element 5 and strikes a reference diode 7, whereby a flash reference measurement is possible.

The majority of the light emitted by the lamp 3 is deflected and enters a beam path 8 which ends above the sample 9 located in the vessel 2 of the sample container.

A fluorescence condenser 10 is provided in the beam path 8. The imaging properties of the fluorescence condenser 10 enable a high reduction in the size of the light spot. This makes it possible to measure microtiter plates with vessels 2 (wells) of different sizes.

The high aperture of the fluorescence condenser 10 and the short distance to the sample 9 enable the capture of a large amount of fluorescent light and thus the improvement of the detection limit.

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Due to the different wavelength of the excitation light, the emission light reaches the detector 13 without deflection from the sample 9, which is formed by an electron tube with a photocathode.

Filter slides 14 with various interference filters and/or polarizing filters 11 are provided in both beam paths. The filters 11 are moved into the operating position depending on the desired wavelength. During the polarization measurement process, switching between parallel and crossed alignment is achieved by a selected displacement of the filter slides 14.

The beam splitter carriage 6 is movable, preferably displaceably mounted, in the carrier housing 1. By means of the beam splitter carriage 6, various beam splitters 5 can be brought into the working position, i.e. to the intersection point of the beam paths 4, 8, whereby several examinations can be carried out with one device.

Since at least one exchangeable beam splitter element 16 is mounted in the beam splitter carriage 6, the measuring head according to the invention can be individually adapted to different customer requirements with different beam splitters 5.

The sensitivity of the measuring head according to the invention can be optimized by an automatic height adjustment of the plate transporter.

When measuring in liquids, the focus point should be just below the liquid surface in order to minimize the influence of the inherent fluorescence of the plate bottom on the measurement result.

The measurement of cells at the bottom of the plate is accomplished by an automatic height adjustment of the plate transport. However, the measurement is only carried out from above.

The transmission measurement is carried out by a detector located below the sample. This detector is only used for transmission measurement.

Claims (11)

1. Measuring head for measuring the fluorescence and preferably the transmission of light rays, with a carrier housing, with a light source for the emission of light, preferably flash light, a measuring station with a receiving device for at least one sample container, in particular for receiving microtiter plates, and an evaluation station with a detector, preferably an electron tube with photocathode, for evaluating the emission signals emitted by the sample, characterized in that a beam splitter slide ( 6 ) which can be moved between at least two working positions and in which at least two, preferably several beam splitter elements ( 16 ) with different beam splitters ( 5 ) for different excitation wavelengths are mounted is arranged in the carrier housing ( 1 ). 2. Measuring head according to claim 1, characterized in that at least one of the beam splitter elements ( 16 ) is exchangeably mounted in the beam splitter carriage ( 6 ). 3. Measuring head according to claim 2, characterized in that the exchangeable beam splitter element ( 5 ) is mounted at one end of the beam splitter carriage ( 6 ). 4. Measuring head according to one of claims 1 to 3, characterized in that the carrier housing ( 1 ) has two intersecting beam paths ( 4 , 8 ), wherein a beam splitter element ( 16 ) with a beam splitter ( 5 ) is arranged at the intersection point of the beam paths ( 4 , 8 ). 5. Measuring head according to one of claims 1 to 4, characterized in that in the beam path ( 8 ) leading from the sample ( 9 ) to the detector ( 13 ), which is preferably designed as a photomultiplier, at least one fluorescence condenser ( 10 ) is arranged, which is located between the sample ( 9 ) and the effective beam splitter ( 5 ) of the beam splitter element ( 16 ). 6. Measuring head according to one of claims 1 to 5, characterized in that an interference filter and/or a polarizing filter ( 11 ) is arranged in the beam path ( 8 ) which leads from the sample ( 9 ) to the detector ( 13 ), preferably the electron tube with photoelectrode. 7. Measuring head according to one of claims 4 to 6, characterized in that interference filters and/or polarizing filters ( 11 ) are arranged in both beam paths ( 4 , 8 ). 8. Measuring head according to one of claims 1 to 7, characterized in that a reference diode ( 7 ) is arranged opposite the light source ( 3 ). 9. Measuring head according to claim 8, characterized in that the reference diode ( 7 ) is formed by a diode board. 10. Measuring head according to one of claims 1 to 9, characterized by a height-adjustable plate transporter for the sample containers, the distance of which to the fixed detector ( 13 ) is adjustable. 11. Measuring head according to claim 6 or 7, characterized in that in at least one of the beam paths ( 4 , 8 ) a filter slide ( 14 ) is arranged, in which several interference filters and/or polarizing filters ( 11 ) with different filter properties are located. 12. Measuring head according to claim 11, characterized in that at least one interference filter and/or a polarizing filter ( 11 ) is arranged exchangeably in the at least one filter carriage ( 14 ).