GB2119119A

GB2119119A - Apparatus and methods of staining biological slides

Info

Publication number: GB2119119A
Application number: GB08311478A
Authority: GB
Inventors: Frank W Jackson; David Schlossberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-04-28
Filing date: 1983-04-27
Publication date: 1983-11-09
Also published as: IT8348165A0; FR2526163A1; IL68384A; GB8311478D0; IT1173706B; GB2152700A; ES276671U; DK187083D0; BE896576A; NL8301479A; SE8302406L; AU557345B2; AU1403983A; ES279935Y; FR2526163B1; SE8302406D0; GB8500205D0; NO831492L; DE3313127A1; GB2119119B

Abstract

Method and apparatus for neatly and efficiently coating microscope slides with a staining liquid. One or more slides (20) are dipped into a pool of liquid (60) partially filling a chamber in a container 30. The chamber has a cross-section conforming closely to the slide exterior so that slide immersion causes the liquid level to rise upwardly and cover all those portions of the slides which may contain a specimen to be stained. To stain a multiplicity of slides simultaneously, the slides are clamped in a holder between spacers which hold them parallel and spaced apart by a small predetermined distance, and the clamped slides are then held by the holder during subsequent immersion and removal. A special inexpensive arrangement of case and slidable drawer with wedge-shaped side portions is used to facilitate fast clamping and unclamping of the slides. <IMAGE>

Description

SPECIFICATION Apparatus and methods for staining of biologic slides The invention generally relates to microscopic examination of biologic specimens mounted on glass slides, and specifically involves the staining of such biologic specimens in preparation for microscopic examination. The staining and examining of biologic specimens occurs daily in great numbers in hospital laboratories, emergency rooms, clinics, biology departments, blood banks, and many physicians' offices, veterinarian offices and hospitals. The slides used are of glass and generally have a 1" x 3" face dimension, and a 1 mm thickness. Some slides have a slightly different face dimension of 25 mm x 75 mm or a different thickness of 1.2 mm. The specimsns to be stained and examined may, for instance, be tissue, blood sputum, or urine.The biologic specimens are usually smeared on the glass slide and left to air dry, often with heat or reagent fixation.

To stain a biologic specimen fixed on a glass slide, it is necessary to bring a staining liquid or reagent into contact with the specimen on the slide. For the present purposes it will be understood that the term staining includes application to the specimen of any of various liquids or reagents during a staining process, even if a particular liquid does not itself produce the actual staining.

In one widely used prior art method of staining, the slide is placed horizontally, specimen up, on a rack suspended in a sink. The staining liquid is poured or dripped from a bottle over the slide to flood the specimen. This technique wastes expensive staining liquid, since much more liquid is generally squeezed or dripped than is actually needed for staining. Also, the sink becomes stained and unsightly after a period of time from the overflow liquid. The operator's fingers become stained when the specimen is picked up. When the bottle reagents remain in the sink area for a prolonged period of time, the fluid can deteriorate or become contaminated, intentionally or accidentally.

It generally requires from 6 cc to 8 cc of each reagent to perform a specific examination with the above technique.

A less common alternative prior art method is to place the slide or slides vertically in a rack, and then to dip the rack with the slide to a container of staining liquid. This too uses an amount of dye far in excess of that actually necessary for staining, and, where the reagent is used for more than one slide, contamination often occurs. Likewise, this technique involves pouring liquid from bottles into containers and pouring the staining liquid from containers into sinks.

A third, again less common procedure is to use an automated staining device. Large hospitals with heavy workloads are more inclined to use this method. The machinery involved in such automated method is extremely expensive and can only be justified where the amount of staining is extremely heavy. The cost of such machines prohibits their use in most staining operations. Furthermore, automated staining devices are only available for one or two stains.

According to one feature of the present invention there is provided a system for staining a biologic specimen affixed to one of the opposed faces of a microscopic slide with a staining liquid, a container having a) a cavity therein; b) tracks extending vertically in the cavity to receive and guide the slide when the slide is inserted into the cavity; c) a space within the cavity adjacent to each of the faces of the slide when the slide is inserted into the cavity; and d) a quantity of staining liquid in the cavity; wherein the staining liquid forms a pool at the bottom of the cavity before the slide is inserted, and the staining liquid is displaced into the spaces adjacent the faces of the slide when the slide is inserted into the cavity on the tracks.

According to another feature of the invention there is provided a device for staining a specimen on a microscopic slide, comprising, 1) acontainer, 2) a cavity in the container adapted to receive the slide, having a) a width approximately equal to the width of the slide, b) a thickness approximately equal to twice the thickness of the slide, and 3) tracks in the container for guiding and positioning the slide in the cavity so that a) the width of the slide will extend across the width of the cavity, and b) the thickness of the slide will be positioned centrally of the thickness of the cavity.

According to a further feature of the invention there is provided a system for staining specimens on a plurality of microscope slides, each of said specimens extending by no more than a distance D from one end of its associated slide, comprising: a) a slide holder for holding the other ends of said slides in a clamped assembly with their lower portions extending from said holder in parallel confronting relation to each other; b) a container having a main chamber partially filled with staining liquid, the depth of said liquid in said chamber being less than said distance D;; c) said slides in said slide holder being sufficiently close together, and the walls of said main chamber conforming sufficiently closely to the periphery of said lower portions of said slide when said assembly is inserted downwardly into said pool, that said staining liquid rises in said chamber to cover said specimens.

According to another feature of the invention there is provided a slide holder for releasably clamping a plurality of microscope slides in a temporary assembly in which said slides are disposed parallel to and aligned with each other, with their major faces in closely confronting spaced-apart relation, comprising: a case having opposed side walls spaced apart a distance greater than the widths of said slides, an open bottom, an open front, and track means extending along the inner sides of said side walls adjacent the bottom of said case; a plurality of vertically-disposed spacers having track-engaging means slidingly cooperating with said track means, whereby said spacers can be spaced apart to receive slides between them or compacted to clamp said slides between them, by sliding said spacers along said track means in one direction or the other; a drawer fitting slidingly into said case, said drawer having a front wall and a pair of opposed side walls terminating in a corresponding pair of tapered wedges having sloped, confronting, wedge surfaces; said spacers having a width less than the interior width of said case thereby to provide space between at least the foremost of said spacers and the adjacent side walls of said case, into which spaces said wedges can enter wedgingly when said drawer is pushed inwardly, thereby to compact said spacers and clamp said slides between them;; said sidewalls of said drawer being sufficiently flexible to permit said wedges to be bent outwardly against said side walls of said case when said drawer is closed, thereby to lock said drawer temporarily in fixed position with respect to said case.

According to a further feature of the invention there is provided the method of staining a slide having a specimen on a face of the slide comprising: 1) forming a contained pool of staining liquid; 2) displacing the staining fluid by vertically inserting the slide into the contained pool; and 3) confining the displaced fluid along the faces of the slide to form a film that stains the specimen.

According to another feature of the invention there is provided a method of staining specimens on a multiplicity of microscope slides, each of said specimens extending by no more than a distance D from one end of its associated slide, said method comprising: forming a temporary assembly of said slides by clamping said slides together, with thin spacers between the end portions of said slides opposite from said one ends thereof, and with the remaining portions of said slides extending beyond said spacers in parallel, closely spaced-apart confronting relation to each other;; with said one ends of said slides positioned downwardly, moving said temporarily-assembled slides downwardly to insert said remaining portions of said slides into a pool of staining liquid confined in a chamber having a depth prior to said inserting which is less than said distance D and having a horizontal cross-section fitting sufficiently closely about said inserted assembly that said liquid is displaced upwardly to cover all of said specimens with said staining liquid and thereby stain them; and thereafter lifting said temporary assembly to remove said slides from said liquid, and unclamping said stained slides to permit their removal from said assembly.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a slide staining device.

Figure 2 is a perspective view of a conventional glass slide of either metric or English dimensions.

Figure 3 is a perspective view similar to Figure 1 showing the slide staining device with the cover removed and a slide inserted.

Figure 4 is a view of a conventional slide such as shown in Figure 2, having been stained in the device of Figure 1.

Figures Sthrough 8 are sectional elevational views showing a slide in successive stages of its insertion into the device of Figure 1 of the invention.

Figure 9 is a graph illustrating a principle involved in the steps of Figures 5 through 8.

Figure 10is an enlarged sectional elevational view taken on the line 10-10 of Figure 1, showing in greater detail the interior design of the staining device of Figure 1.

Figure 11 is a transverse sectional view taken on the line 11-11 of Figure 10, showing still further details of construction.

Figure 12 is a plan view of the staining device directly beneath the foil cover taken on the line 12-12 of Figure 10, showing details of the slide entrance aperture on the upper face of the staining device.

Figure 13 is a sectional plan view taken on the line 13-13 of Figure 10, showing the profile and proportions of the interior chamber and slide-guiding slots of the staining device.

Figure 14 is an eniarged sectional elevational view similar to Figure 10, but showing a slide fully inserted in the staining device, such as is shown in Figure 3, and showing the combined proportions and the positions ofthe slide and slide-staining device in use.

Figure 75 is a transverse sectional elevational view taken on the line 15-15 of Figure 14 showing central positioning of a slide carried in slots and showing liquid displacement chambers formed on the front and rear faces of the slide.

Figure 16 is a sectional plan view taken on the line 16-16 of Figure 14, showing relative proportions and positions of the slide and slide-staining device, and liquid displacement chambers formed on the front and rear sides of the slide.

Figure 17 is a perspective view of the multiple slide staining tank of this invention, with the seal cover partially removed.

Figure 18 is an exploded perspective view showing both the slide holder and staining tank of the invention.

Figure 19 is a perspective view of both the slide holder and staining tank in a co-acting condition in accordance with this invention.

Figure 20 is a perspective view of the empty slide holder of this invention prior to loading.

Figure 21 is an exploded perspective view of the slide holder shown in Figure 20 showing all the co-acting elements of the slide holder of this invention.

Figure 22 is a perspective view of the slide holder of Figures 20 and 21 being loaded with five slides to be stained.

Figure 23 is a sectional elevational view taken on the line 23-23 of Figure 22, showing the five slides loaded in the holder, prior to clamping therein.

Figure 24 is a sectional plan view taken on the line 24-24 of Figure 23 showing additional details of the five loaded slides loosely held by the slide holder.

Figure 25 is a sectional elevational view similar to Figure 23 but showing the five slides clamped in tightly held spaced relationships, and with the five slides extending in planes normal to the top and bottom faces of the slide holder.

Figure 26 is a view similar to Figure 24, but showing the slides in a clamped position.

Figure 27 is a side sectional elevational view of the slide staining tank taken on the line 27-27 of Figure 17, showing interior details of the tank.

Figure 28 is a front sectional elevational view of the slide staining tank taken on the line 28-28 of Figure 17, showing additional details of the tank interior.

Figure 29 is a side sectional elevational view taken on the line 29-29 of Figure 19, showing details of the tank interior when in engagement with the loaded slide holder.

Figure 30 is a front sectional elevational view taken on the line 30-30 of Figure 29, showing additional details of the tank interior when engaged with the loaded slide holder and showing the resultant upward displacement of a staining fluid about the slides.

A conventional slide 20 is shown particularly in Figures 2 and 4. The slide 20 is simply a rectangular piece of glass 21 on which a specimen 22 is mounted for microscopic examination. The slide has opposed flat surfaces or faces 23 and 25, opposed long edges 26 and 27, and opposed short edges 28.

The most commonly used slide has a lengh (Ls) of approximately 3", a width (Ws) of approximately 1", and a thickness (Ts) of approximately 1 mm. In some instances, the slide may have a Ls of 75mm and Ws of 25mm, or a Ts of 1.2mm.

These dimensions may vary slightly with different manufacturers. For instance, thicknesses may vary from .0525" to .0325", and the width may vary from 1.016" to .964".

The specimen 22 is prepared and then affixed to a face of the slide in any well known manner such as by use of air drying, heat, or reagent fixation. The specimen 22 is generally positioned at the center of one of the slide faces, with a clear zone, free of the specimen, on each end of the face. The specimen is virtually invisible at this point, prior to staining.

The slide 20, with the unstained specimen 22 thereon, is intended to be inserted into a disposable slide-staining device 30. Device 30 is desirably formed of a transparent or translucent plastic into a generally long rectangular configuration having proportions generally conforming to the proportion of the slide 20.

The device is intended to be used vertically, and has a top 31, a bottom 32, edges 33 and sides 35 and 36. A collar or flange 29 surrounds top 30 and has a flat surface thereon.

An internal cavity or chamber 40, likewise is rectangular in configuration and again, conforms generally to the proportions of the slide 20. The internal cavity 40 has opposed tapered vertical tracks 41 and 42, along the vertical edges 43 and 45 of the cavity extending from the top 40 of the cavity to the bottom 47. The cavity also has opposed sides 48 and 49.

The cavity 40 has at its upper end a sloping, downwardly converging portion 51 having beveled edges 52 and sides 53.

A cover or seal 55 is affixed to the top 31 on collar or flange 29 by suitable means, such as heat sealing or adhesive. The cover is intended to be peeled back by grasping and pulling on tab 56 prior to use, so that the cavity 40 is exposed.

A pool of sustaining liquid 60 is contained within the cavity and extends about halfway up the cavity, as seen in Figures 1 and 10.

The device is intended to be manufactured at a central facility whereat it is sealed with the staining liquid therein, as seen in Figure 1.

As seen in Figures 5 through 8, there is shown in sequence views of a slide 20 being inserted into the cavity 40. In Figure 5, the slide 40 with a biological specimen 22 to be stained affixed thereon, is shown entering the cavity 40 on tracks 41 and 42. The slide 20 is spaced from the opposing sides 48 and 49 as seen best in Figures 15 and 16. The slide in Figure 5 is just about to contact the upper surface of the pool 60, which is the static liquid level. The static liquid level is at a height of H1 above the bottom of the cavity.

In Figures 6 and 7, the slide progressively descends into the cavity below the pool, the liquid in the pool is displaced and rises until the dynamic fluid level reaches H2 as seen in Figure 8, when the slide is fully inserted. At this point, the staining liquid entirely covers specimen 22. H1 is approximately one-half of H2. H2 also represents the heighth of the cavity as seen best in Figure 14.

In Figure 9, the principle described and shown in Figures 5 through 8 is illustrated in graph form. As the slide is submerged below the static liquid level, there is a corresponding rise in the dynamic liquid level of the staining liquid in virtually a straight line relationship.

As the slide is removed from the staining liquid, after being left therein for an adequate period to accomplish staining, the slide is withdrawn and the reverse sequence occurs. The liquid level falls correspondingly as the liquid drains from the side of the slide into the pool. There is some residual staining liquid that adheres to the specimen and the slide, and of course the pool heighth at the end of staining drops correspondingly below the static liquid level, when the slide is withdrawn from the device. The slide when withdrawn from the device 30 has thereon the stained specimen 54 as seen in Figure 4. Since the device is intended for a one-time use, such drop in the pool heighth and volume is not objectionable.

The tapered or guide portion 51 with beveled edges 52 and beveled side 53 permits easy insertion of the slide into the tracks. It also acts as a well to catch any overflow of the staining liquid, including any splashing where the slide is dropped rapidly into the cavity. A collar or guide portion 29 extends around the upper end or top of the device and is integral therewith. Flange 29 has desirably a flat top portion 63 which permits a foil or cover 55 to be suitably secured thereto as by adhesive, or by a suitable heat-sealing technique. The foil can be of a metallic or a plastic material capable of being peeled back from the covering by grasping a tab portion 56 and pulling to a compietely open position, as seen in Figure 3. The cap portion in sealing and covering position is shown in Figures 10 and 11.

There is variability in the width and thickness of slides, even those claiming to have specific dimensions.

By tapering the tracks, the device will receive a slide of variable thickness and variable width and still keep the slide away from the inside wall of the cavity. Additionally, the tapered tracks assure that only the edge of the slide will touch the track and not the surface which contains the specimen.

The slide 20 when inserted into the cavity 40 on the tracks 41 and 42 assumes a very definite position and posture within the cavity and with respect to the sides or walls 48 and 49 of the cavity 40.

As seen in Figures 14 to 16 inclusive, the slide 20 when inserted into its bottommost position has a top portion 61 which extends above the cavity 40 and top 31 of the device 30. The top portion 61 of the slide 20 is clear of any specimen 22, since the specimen zone is conventionally in the middle of the slide as shown in Figure 14 by phantom lines. The portion 61 of the slide 20 remaining above the device 30 is used to grasp the slide from inserting into the device and for withdrawing the slide from the device. The slide is also grasped by this portion during the rinsing subsequent to the staining. In this way, the operator's fingers remain free of contact with the staining solution, and free of the dye. Approximately one-sixth of the length of the slide Ls extends above the device 30.

The specimen 22 is stained when the slide is fully inserted as shown particularly in Figures 14 through 16 inclusive. The slide as seen particularly in Figures 15 and 16 is positioned centrally of the cavity 40 and spaced from walls or sides 48 and 49. The slide 20 has adjacent to each face thereof spaced 65 and 66 which contain staining liquid. The slide can be inserted with the specimen 22 facing in either direction as the slide 20 enters the cavity. The face of the slide 20 and the specimen 22 thereon is positioned so that the specimen 22 cannot contact the sides of the cavity, but rather the specimen is held in a way that exposes it to the staining liquid in the space 65 or 66 formed by the slide and the side of the cavity. A minimum amount of staining liquid is necessary to stain the specimen when the slide is so positioned.This is clearly shown in the sectional views in Figures 15 and 16.

It will be seen from the above description that the space 65 and 66 adjacent to each face of the slide when the slide is fully inserted into the cavity is a flat thin space which contains a suitable amount of staining liquid to properly stain the specimen thereon, without excess use of such liquid. Furthermore, the slide itself is used to position this liquid adjacent to the faces of the slide, and the specimen on one of the faces. It will be seen that it does not matter as to which direction the specimen faces when inserted into the cavity, since there is film on both faces of the slide.

The slide itself, in cooperation with the container, creates the film adjacent to the slide faces for staining, and then permits the liquid in those spaces to drain back into the bottom of the cavity and pool formed therein when the slide is removed.

In Figures 10 through 16 inclusive, there is shown in detail the interior of the device of Figure 1. Ws is the width of the slide 20, Ls is its length, and Ts is its thickness. H2, which is the heighth of the cavity, as well as the heighth of the dynamic liquid level discussed above, is approximately three-quarters of the slide length Ls The tracks 41 and 43 comprise tapered walls in the edges of the cavity, as shown. The width between the tracks, WT, as seen in Figure 13, is slightly greater, for instance, .02" greater, than the width of the slide Ws, so that there is adequate clearance for the slide to move in the tracks. TT, the thickness of the track at its tapered end, is slightly less, for instance, .016" less, than the thickness of the slide Ts. Y, the thickness of the cavity, is approximately twice the slide thickness, Ts. By virtue of the tapered tracks 41 and 42, the slide, when inserted in the tracks, is centrally spaced between the side walls of the cavity, 48 and 49. Where the thickness of the cavity is twice that of the slide, the thickness of the spaces formed on each face of the slide when the slide is inserted will be approximately one-half the thickness of the slide.

By virtue of the tapered tracks 41 and 42, slides with slightly varying dimensions as set forth above will be suitably spaced within cavity 40. The tapering walls of the tracks 41 and 42 will compensate for these slight variations by guiding the slide at its edges thereof while still positioning the slide. Even with a slide having the smallest width and/or thickness within the variable dimensions, the slide is still spaced from the sides of the cavity, although all edges of the slide may not be in form contact with the tracks. Even though such a relatively small slide may have more freedom to move about within the cavity than a relatively large slide, the restraint imposed on the corners of the slide by the tapered walls of the tracks keeps the slide spaced from the cavity wails so that a film of staining fluid can be formed adjacent the slide faces.

It should be understood that the dimensions given above are merely illustrative to indicate a suitable dimensioned container to practice the invention.

Referring now to an alternative embodiment of the invention for simultaneously staining a multiplicity of slides, and with particular reference to Figures 17-30, slides 120 are of the nature, size and design described above with respect to slide 20.

The container 130 may be generally similar to the container 30 described above, in shape, heighth, and width, except the horizontal depth of the container is extended to receive a plurality of slides, rather than only one, as will be described. The container 130 has an open top 131, a bottom 132, edges 133, 134, sides 135, and 136, and collar or flanges 129.

The internal cavity or main chamber 140 of container 130, has four tracks such as 141 and 142 in its four vertical corners, vertical edges 143 and 145, a bottom 147, and opposed sides 148 and 150.

In the version shown, the main chamber has at its top a overflow chamber 160 formed in the flange portion 129 which has side walls 168,170 formed by sides of the main chamber 140, end walls 172,174 and bottom ledges such as 180.

A seal cover 186, similar to seal 55 described above, is affixed to top 131 of the container.

The slides are spaced, positioned, and securely held in holder 200, which consists essentially of a drawer 202, a case 204, and spacers such as 206. The spacers are slidably and pivotally suspended in case 204 on pivottrunion pins such as 210 which ride in tracks 212 and 214 on the interiors of the opposed sidewalls 215,216 of the case. Drawer 202 slides into case 204 so that when moved inwardly it pushes against at least the foremost spacer 217.

The case 204 has a closed top wall 218 and an open bottom. (The case is shown inverted, in the loading position, in Figures 20, 21, 22, 23 and 25). The side walls 215,216 contain respective slots 224 and 226, an open front and a closed back wall 230.

The tracks 212 and 214 in the case 204 are each formed by parallel ridges which define channels 232,234 for receiving the pins 210 on the spacers.

The spacers are thin, flat rectangles which preferably have, at their long edges nearest the pins, a tapered edge or point for facilitating insertion between them of one end of the slides. The pins are near the edges of the spacers so the spacers hang free and loose in the tracks before loading of the slides. Preferably, these spacers are all alike.

The drawer 202 has a front wall 300, push and pull knobs or ears 302,304 at the opposite sides of the front wall, sides 306,308, and diagonal interior braces 310,312 extending between the front wall and the side walls of the drawer. The side walls 306,308 each have a cam tooth such as 314 intended to ride in a corresponding slot such as 226 in the side wall of the case when the drawer is inserted into the case. The drawer side walls fit inside of, and in sliding engagement with, the case side walls. Each of the cam teeth 314 has a sloping surface such as 320 which permits the drawer to be inserted into the case until the teeth engage in their corresponding slots 224 and 226, after which the flat end surface 322 on the tooth prevents the drawer from unintentionally being pulled all the way out of the case.

The drawer is desirably made of a relatively flexible plastic material such as polyethylene, wherein there is a degree of give, particularly to the sides beyond the braces, for purposes which will be explained later. The spacers are likewise desirably made of such flexible material.

In contrast to the drawer and spacers, the case is made of a relatively rigid material such as glass-filled nylon, so that the relatively flexible drawer and spacers, in combination with the relatively rigid case, will permit the drawer to lock the spacers to the case as described hereinafter.

It is intended that container 130 contain a confined or limited pool of staining fluid 360. As best seen in Figures 27 and 28, this pool extends to a height H, which is preferably somewhat over one-half of the height of the chamber 140.

As with the single slide embodiment shown in Figures 1 through 16, it is intended that slides 120 be inserted downwardly into this pool 360, whereby staining liquid of the pool will be displaced upwardly in the main chamber substantially to the top thereof without overflowing into the overflow chamber, but in the event of excess upward flow of displaced liquid this may be caught in the overflow chamber 160. In a preferred design, the proportion of parts and depth of pool are such that no substantial overflow occurs, and in such case the large overflow chamber can be eliminated and the top of the container made as in the single-slide version of Figures 1-16.

The slides are held in exact spaced relationship with each other and the container so that a thin film is formed on both sides of the slides. The space between the slides conforms to the thickness of the spacers.

Desirably, this thickness is approximately equal to the thickness of the slides themselves, which is indicated above can be about 1 mm. The spacing is such that when the spaced slides are secured in the holder, and the slides are immersed in the limited pool in the container substantially to the bottom thereof, the pool will be displaced so that the staining liquid rises in thin films which reach and covers substantially all the slide portion which extends into main chamber of the container, and particularly the portions to which the specimens are affixed.

The positioning and spacing of the slides are accomplished in the holder, which initially is placed on its top, in an inverted position. The spacers are allowed to hang freely on their trunnion pins in tracks 212,214 as seen in Figures 22, 23 and 24. At this time, the drawer 202 is open, and side walls 306 and 308 of the drawer are parallel and in a relaxed position, whereby the drawer can slide freely in the case, except that the drawer cannot be withdrawn completely out because of the interfering action of cam teeth 314.

As shown in Figure 22, slides 120 are then inserted between the spacers such as 206, with the beveled edges of the spacers aiding entry of the slides between the spacers. The spacers and slides are preferably of the same width. The width of the case between its side walls is equal to the width of the slides plus a slight clearance dimension. During assembly, the slides are dropped to the "bottom" of the inverted case, so that the straight edges of the ends of the slides rest on the interior of the top wall of the case. When the necessary number of slides has been inserted in the holder, which is five for the five-slide holder and container embodiment shown, the drawer is pushed closed from the position shown in Figures 23 and 24 to the position shown in Figures 25 and 26.

Sidewalls 306 and 308 of drawer 202 terminate at their free ends in respective wedges 370, 372 having respective, confronting, tapered wedging surfaces 374,376 adapted to enter the above-mentioned clearance between spacers and side walls when the drawer is closed. Also, when the drawer is closed, the outer ends of sidewalls 306 and 308 are spread outward due to the wedging actions of surfaces 374,376 against the ends of the spacers. The wedges are formed in the side walls beyond the braces 310, 312, so that the side walls are held relatively parallel up to the end of the braces, while the remaining outer end portions of the side walls are relatively free to flex outward under the influence of the spacers, and against the inside of the side walls of the case.The resistance of the spacers are slides against the wedges therefore serves to jam the wedges against the side walls of the drawer, so that the drawer, the slides and the spacers are locked in position, with the slides clamped between the spacers. The spacers, which are relatively flexible, give slightly against the hard glass of the slides and then serve to cushion-grip the slides. The slides are now held parallel to one another, and evenly spaced from each other by predetermined distances.

If there is any slight misalignment of the slides because the ends of the slides are not touching the interior of the case top, or because the slide ends are not entirely square with the slide sides, any such slight misalignment can be remedied by forcing the slides into the correct position manually, with one's fingers.

The outside dimensions of the five-slide group extending from the holder closely conform to the chamber designed for the five-slide staining operations. These dimensions are such that when the holder is inverted from the loading position and the exposed portions of the slides inserted into the container, the edges of the outside slides touch the sides of the tracks such as 141,142 in the container, whereby, when the slides, by means of the holder are inserted into the container, there is formed a thin space adjacent to each of the outside faces of the outside slides. The tracks such as 141,142 can be molded integrally with the remainder of the container, and may have lead-in bevels at their entrance ends to facilitate insertion of the slide assembly.

As the slides are immersed into the pool, the liquid is displaced upwardly along the slide faces. The dimension of the portion of the slides extending into the holder is preferably such that when the holder comes into contact with the top of the container, the slides almost touch or are just slightly above, the bottom of the container. Thus, essentially all of the staining liquid at this time extends in thin films across the faces of the slides, and across the specimens on the slides. The liquid rises to the top of the chamber, and permissibly into the overflow chamber if one or more of the slides is slightly thicker than a generally standard slide.

When the specimens have been thus stained, the slides are withdrawn from the container by means of the holder. The staining fluid drains off the slides, back into a pool of approximately the same size as the beginning pool minus the quantity which adheres to the slide. The container can permissibly be resealed with the original seal, and then neatly discarded. The holder and slides are then inverted and the slides unloaded from the holder in essentially a reverse operation from the loading operation described above.

In order to withdraw the drawer from the case and to release the grip of the spacers on the slides, it is necessary to break the wedging action of the sides of the drawer. To do this, the drawer is gripped at its ears 302 and 304 between the fingers, and an alternating rocking motion is exerted on the drawer as the drawer is withdrawn from the case, which is anchored by the fingers of the operator's other hand. The case is desirably resting on a table during the unloading operation. After the jamming and wedging action of the drawer is thus broken, the drawer is withdrawn to release the spacers and slides to the position shown in Figures 23 and 24. The slides an then be delicately removed from the holder and further processed by rinsing and the like, in the usual way.

The holder can optionally be washed and rinsed and then used with a new container and pool, orthe holder can be thrown away.

It is intended that the container and holder be mass-produced out of plastic, by, for instance, extrusion molding, so that the cost per unit be relatively low.

The above embodiment is illustrated with a five-slide group. It should be understood that the same principle can be used with respect to any desired group from, for instance, two to ten and beyond, with each having its specifically dimensioned container, holder, and pool. However, it is contemplated that the five-slide arrangements will be the most prevalent.

Two such five-slide holders can also be clipped back-to-back to create a ten-slide holder. Such ten-slide combination may then be inserted into a ten-slide container, designed in accordance with the invention to accommodate the ten slides.

The container shown above has an overflow compartment as described. This is generally desirable when it is anticipated that the slides used vary somewhat in their thickness. Since a thicker slide displaces more liquid, the overflow chamber serves to receive and hold this overflow during the staining operation. Where the slides are relatively uniform in thickness, there is no need for an overflow chamber, since the displacement is more controlled. In this condition, the overflow chamber can be reduced in size, or eliminated, as seen in the embodiment shown in Figures 1 to 16.

As an aid in design, the following relations are noted. The distance H2 by which the level of the top of the pool of staining liquid is raised by immersion of the slides is equal to the volume of the liquid displaced upwardly by the glass of the slides, divided by the average cross-sectional area of the glass-free chamber space into which the liquid is displaced.Designating the distance by which the slides are immersed below the top of the original pool as H1, the average cross-sectinal area of the chamber above the original pool surface with the slides removed as Ach, and the average cross-sectional area of slide glass in the liquid as Agi, then H1 H2 = Ach/Agi - 1 In the simple case of a purely rectangular chamber, five slides of 1 mm thickness each spaced from each other and from the chamber walls by 1 mm, and immersion of the slides to the full depth H of the original pool, the formula predicts a rise in liquid level H ~ H H2= 11/5-1 1.2 = = .83H.

In practice, the height H2 will be reduced below this value by any extra chamber space at the edges of the inserted slides, and increased due to reductions in chamber space caused by tracks in the chamber.

While the invention has been described with particular reference to specific embodiments in the interest of complete definiteness, it will be understood that it may be embodied in a variety of forms diverse from those specifically shown and described, without departing from the scope of the invention as defined by the appended claims.

Claims

1. In a system for staining a biologic specimen affixed to one of the opposed faces of a microscopic slide with a staining liquid, a container having a) a cavity therein; b) tracks extending vertically in the cavity to receive and guide the slide when the slide is inserted into the cavity; c) a space within the cavity adjacent to each of the faces of the slide when the slide is inserted into the cavity; and d) a quantity of staining liquid in the cavity; wherein the staining liquid forms a pool at the bottom of the cavity before the slide is inserted, and the staining liquid is displaced into the spaces adjacent the faces of the slide when the slide is inserted into the cavity on the tracks.

2. A container of claim 1 wherein the volume of the pool is approximately equal to the spaces adjacent to the faces of the slide.

3. A container of claim 1 wherein the space adjacent to the face of the slide having the specimen fixed thereon covers the specimen when the slide is fully inserted into the cavity.

4. A container of claim 1 wherein the space adjacent the face of the slide is flat and has a thickness less than the thickness of the slide.

A container of claim 4 wherein the space has a thickness approximately equal to one-half the thickness of the slide.

6. A container of claim 1 wherein the pool at the bottom of the cavity is displaced upward in the space to a heighth approximately twice the heighth of the pool prior to the slide's being inserted.

7. A container of claim 1 wherein the container has a height less than the length of the slide.

8. A container of claim 1 wherein a portion of the slide extends without the container when the slide is fully inserted into the cavity, whereby the slide can be held during its insertion and withdrawal into and out of the cavity.

9. A container of claim 1 wherein the tracks are tapered in cross section.

10. A staining device for biologic specimens fixed on glass slides, comprising: 1) Acontainer; 2) a track fixed within the container on which the slide can be moved vertically into a downward position; 3) a cavity within the container having walls surrounding the track forming a) a confined volume around the track, and b) a space on each face of the slide in the confined volume when the slide is in a downward position on the track; and 4) a pool of staining liquid at the bottom of the track that is displaced by the slide in the downward position into the spaces on each face of the slide.

11. A device of claim 10 wherein the space on the face of the slide is flat and covers the specimen on the slide.

12. A device of claim 10 wherein the track is tapered in cross section.

13. A device of claim 11 wherein the thickness of the space adjacent the face of the slide is less than the thickness of the slide.

14. A device of claim 13 wherein the thickness of the space adjacent the face of the slide is approximately equal to one-half the thickness of the slide.

15. A device for staining a specimen on a microscopic slide, comprising, 1) a container; 2) a cavity in the container adapted to receive the slide, having a) a width approximately equal to the width of the slide, b) a thickness approximately equal to twice the thickness of the slide; and 3) tracks in the container for guiding and positioning the slide in the cavity so that a) the width of the slide will extend across the width of the cavity, and b) the thickness of the slide will be positioned centrally of the thickness of the cavity.

16. A device of claim 15 wherein the tracks are tapered in cross section.

17. A device of claim 15 wherein the heighth of the cavity is approximately equal to five-sixths of the length of the slide.

18. A device of claim 15 wherein the slide when inserted into the cavity forms a flat space adjacent each face of the slide.

19. A device of claim 15 wherein the flat space has a thickness approximately equal to one-half the thickness of the slide.

20. A device of claim 15 in combination with a pool of staining liquid within the cavity.

21. A device of claim 15 in combination with a pool of staining liquid within the cavity.

22. A device of claim 21 in combination with a removable seal over the cavity.

23. A device for staining with liquid a specimen fixed on the face of a micropscopic slide comprising 1) acontainer, 2) a cavity within the container having a first space for receiving the slide and a second space extending parallel and adjacent to the first space to contain a flat film of liquid when the slide is within the container, the thickness of the second space being less than the thickness of the first space, and 3) tracks in the container for guiding the slide into the first space wherein the second space covers the specimen on the face of the slide when the slide is within the container.

24. A device of claim 23 wherein the tracks are tapered in cross section.

25. A device of claim 23 in combination with a volume of staining liquid which forms a pool at the bottom of the cavity when the slide is without the cavity, and which extends into the second space when the slide is within the cavity.

26. A device for staining a biological specimen comprising: 1) a container having a) a cavity of rectangular cross section, b) a heighth less than the heighth of the slide, 2) tracks in the container for guiding the slide vertically into and out of the cavity; and 3) a pool at the bottom of the cavity; wherein when the slide is out, the pool surface is substantially at one-half the heighth of the cavity, and when the slide is fully inserted, the pool is displaced to the top of the cavity.

27. A system for staining specimens on a plurality of microscope slides, each of said specimens extending by no more than a distance D from one end of its associated slide, comprising: a) a slide holder for holding the other ends of said slides in a clamped assembly with their lower portions extending from said holder in parallel confronting relation to each other; b) a container having a main chamber partially filled with staining liquid, the depth of said liquid in said chamber being less than said distance D; c) said slides in said slide holder being sufficiently close together, and the walls of said main chamber conforming sufficiently closely to the periphery of said lower portions of said slides when said assembly is inserted downwardly into said pool, that said staining liquid rises in said chamber to cover said specimens.

28. The apparatus of Claim 27, wherein said container comprises guide means for holding the outer faces of the end slides in said assembly spaced from the walls of said chamber.

29. The apparatus of Claim 28, wherein said main chamber has a generally rectangular cross-section and said guide means comprises four vertical walls extending across the corners of said chamber for contacting the four corners of said end slides guidingly.

30. The system of Claim 27, wherein said slide holder comprises: a case having a pair of side walls, a top wall, a back wail, an open bottom and an open front; and a clamping drawer adapted to slide in and out of the open front of said case; said case containing a plurality of slide spacers for receiving said slides between them and having track means in its opposed side walls slidably mounting said slide spacers for motion toward and away from said back wall; said clamping drawer having spacer contacting means formed integrally with said side walls for compacting said spacers when said drawer is advanced in its closing direction, thereby to clamp said slider between said spacers.

31. The system of Claim 30 wherein said spacer contacting means comprises wedge means responsive to motion of said drawer in its closing direction to bewedgingly inserted between at least one of said spacers and at least one adjacent wall of said case, thereby to lock said slides and said spacers releasably in said clamped assembly.

32. The system of Claim 31 wherein: each of said spacers comprises a pair of trunnions extending from opposite sides thereof and into said track means; wherein each of said spacers is narrower than the distance between said side walls, so as to leave openings at each end of the spacer between spacer and adjacent side wall; and wherein said wedge means comprises a pair of forwardly-extending wedges, one adjacent each of said side walls, and aligned with said openings between said spacers and said side walls.

33. The system of Claim 32 wherein said container comprises an overflow chamber of greater horizontal cross-section than the main chamber for receiving excess displaced liquid from said pool.

34. A slide holder for releasably clamping a plurality of microscope slides in a temporary assembly in which said slides are disposed parallel to and aligned with each other, with their major faces in closely-confronting spaced-apart relation, comprising: a case having opposed side walls spaced apart a distance greater than the widths of said slides, an open bottom, an open front, and track means extending along the inner sides of said side walls adjacent the bottom of said case; a plurality of vertically-disposed spacers having track-engaging means slidingly cooperating with said track means, whereby said spacers can be spaced apart to receive slides between them or compacted to clamp said slides between them, by sliding said spacers along said track means in one direction or the other;; a drawer fitting slidingly into said case, said drawer having a front wall and a pair of opposed side walls terminating in a corresponding pair of tapered wedges having sloped, confronting, wedge surfaces; said spacers having a width less than the interior width of said case thereby to provide spaces between at least the foremost of said spacers and the adjacent side walls of said case, into which spaces said wedges can enter wedgingly when said drawer is pushed inwardly, thereby to compact said spacers and clamp said slides between them; said sidewalls of said drawer being sufficiently flexible to permit said wedges to be bent outwardly against said side walls of said case when said drawer is closed, thereby to lock said drawer temporarily in fixed position with respect to said case.

35. The slide holder of Claim 34 wherein said drawer comprises braces extending between the front wall of said drawer and positions on said side walls thereof short of said wedges, whereby positions of said lastnamed side walls short of said wedges are held rigid while said wedges are free to be bent ouwardly during said locking action thereof.

36. A method of staining biologic specimens using: 1) moving the slide vertically downward relative to and within the container to the bottom thereof; and 2) displcing the liquid of the pool upward relative to the container by means of the slide; wherein a) the pool is substantially one-half of the container heighth before the slide moves vertically downward, and b) the liquid in the pool is displaced upwardly to substantially the full container heighth when the slide is moved vertically downwardly to the bottom of the container.

37. The method of staining a specimen on a microscopic slide comprising 1) containing a pool of staining liquid in a cavity, wherein the pool is one-half the cavity heighth; 2) confining the pool in the cavity so that it can only be displaced inwardly; 3) inserting a slide having a specimen fixed thereon into the pool; and 4) displacing the pool up along the slide to substantially the top of the cavity.

38. The method of staining a slide having a specimen on a face of the slide comprising: 1) forming a contained pool of staining liquid; 2) displacing the staining fluid by vertically inserting the slide into the contained pool; and 3) confining the displaced fluid along the faces of the slide to form a film that stains the specimen.

39. The provess of staining a specimen on a face of a microscopic slide comprising: 1) moving the slide downward relative to a container having a pool of staining liquid therein; and 2) displacing the liquid in the pool upward relative to the container wherein the surface of the liquid is moved upward to approximately twice its original heighth.

40. The process of using a slide to form a film of staining fluid on its sides comprising moving the slide downward into a pool of staining liquid whereby the pool is displaced upward to form a film over each of the faces of the slide.

41. The method of staining specimens on a multiplicity of microscope slides, each of said specimens extending by no more than a distance D from one end of its associated slide, said method comprising: forming a temporary assembly of said slides by clamping said slides together, with thin spacers between the end portions of said slides opposite from said one ends thereof, and with the remaining portions of said slides extending beyond said spacers in parallel, closely spaced-apart confronting relation to each other;; with said one ends of said slides positioned downwardly, moving said temporarily-assembled slides downwardly to insert said remaining portions of said slides into a pool of staining liquid confined in a chamber having a depth prior to said inserting which is less than said distance D and having a horizontal cross-section fitting sufficiently closely about said inserted assembly that said liquid is displaced upwardly to cover all of said specimens with said staining liquid and thereby stain them; and thereafter lifting said temporary assembly to remove said slides from said liquid, and unclamping said stained slides to permit their removal from said assembly.

42. The method of Claim 41, comprising quiding opposite edges of at least one of said slides during said inserting and removal of said assembly to prevent contact between the walls of said chamber and the faces of the end slides in said assembly.

43. The method of Claim 41, wherein said clamping of said slides comprises loosely supporting said spacers parallel to each other in a slide holder, inserting said end portions of said slides between said spacers, compacting said slides and spacers, and inserting wedge means between said compacted assembly and said slide holder; and wherein said unclamping comprises loosening said wedge means from between said compacted assembly and said slide holder.

44. Apparatus for staining a specimen on a microscopic slide substantially as herein described with reference to Figures 1 to 16 or Figures 17 to 30 of the accompanying drawings.

45. Methods of staining a specimen on a microscopic slide substantially as herein described with reference to the accompanying drawings.