Patent Publication Number: US-7217394-B2

Title: Apparatus for handling biopsy specimens, and method for using it

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of the Swiss patent application 0257/02 which is incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The invention refers to an apparatus for handling biopsy specimens, and to a method for using it. 
     BACKGROUND OF THE INVENTION 
     Modem electron microscopy of biological specimens is more and more frequently examining specimens that have been immobilized by freezing (cryofixation). Freezing must be performed in such a way that the specimens vitrify, i.e. so that upon cooling, no ice (which would segregate the specimen) can form. “Segregation” is the separation of the specimen into pure water (ice crystals) and concentrated dissolved substances between the branches of the ice crystals. In vitrification, water is immobilized in its liquid configuration. In other words, all the constituents of the biological specimen are not displaced during immobilization, and thus represent a “snapshot” of the living material at the moment it was fixed. Vitrification in a biological system is a rapid process: a freezing rate of several 100,000 K/s is normally necessary. For physical reasons, such high freezing rates can be achieved only in very thin specimens (thickness &lt;20 μm). The critical freezing rate necessary for vitrification can be reduced by a factor of 100 if the specimen is frozen at a pressure of approximately 2000 bar. In so-called high-pressure freezing (Studer et al., Journal of Microscopy 179 (1995), 321–332), biological specimens approx. 200 μm thick are vitrified. Production of a 200 μm-thick specimen with a diameter of 1.2 to 3 mm is difficult. The advantages of high-pressure freezing are reduced if a great deal of time is spent preparing the biological specimens, e.g. a piece of tissue, for freezing. Individual attempts at rapid preparation of very small tissue pieces have been described by various authors (H. Hohenberg et al., Journal of Microscopy 183 (1996), 133–139; E. Shimoni et al., Journal of Microscopy 192 (1998), 236–247). Shimoni et al. fired small metal capillaries (gold tubules with an inside diameter of 200 μm) into the tissue; locating these capillaries in the tissue is time-consuming, however, and the frozen specimens are difficult to process. Hohenberg et al. (1996) took tissue samples 0.2–0.25×0.4×4–8 mm in size from experimental animals, using commercially available microbiopsy needles adapted for that particular purpose. 
     Commercially obtainable apparatuses for taking microbiopsy samples from living tissue have a spring mechanism (gun) that receives a needle (for example, Pro-Mag™, Manan Medical Products, Inc., Northbrook, Ill. 60062, USA). This biopsy needle in turn comprises a solid lance (diameter 0.6–3 mm) having an opening, 8–16 mm long and 0.3–2 mm deep, for receiving the biopsy material (Hohenberg op. cit. FIG. 1-D, pp. 134–35). This lance is pointed at one end, and has a holding device at the other end. This lance is in turn surrounded by a thin-walled hollow needle whose inside diameter corresponds to the outside diameter of the lance, so that the lance and hollow needle are displaceable with respect to one another. The hollow needle has a cutting edge at one end and a holding device at the other. 
     The hollow needle, and the lance inserted in it, are secured with the holding devices in the gun, so that the mechanism for removal of the biopsy material is as follows: First the needle, inserted into the gun, is introduced into the tissue, so that the hollow needle allows only the tip of the lance to protrude. Then the spring mechanism is released. As a result, firstly the lance is advanced farther into the tissue so that the opening is no longer enclosed by the hollow needle. The tissue enters the opening, and at the next instant the hollow needle with the cutting edge is in turn slid over the opening by the spring mechanism. The piece of tissue present in the opening is thereby cut off. The hollow needle, together with the lance, is then pulled back out of the tissue, and the outer hollow needle is once again slid back with respect to the lance so that the cut-out specimen becomes accessible. 
     Biopsy specimens obtained in this fashion have, for example, the following dimensions: 200 to 250 μm high, 400 μm wide, and 4 to 8 mm long (Hohenberg, op. cit., p. 135). These specimens are manually reduced in size using suitable cutting tools (razor blades, scalpels, or the like), cut to the correct size, and transferred with forceps or other suitable instruments into the specimen plates of appropriate high-pressure freezing units. 
     This manual preparation of biopsy specimens for high-pressure freezing exhibits, however, a number of serious disadvantages which reveal this method to be unsuitable for larger quantities of specimens and especially for routine operation. The elapsed time between excision of the biopsy material and the beginning of the freezing operation has been quoted as approx. 40 seconds (Hohenberg op. cit. p. 135); experience has shown, however, that this is a very optimistic time scale. This elapsed time is obviously too great, particularly in cases in which “snapshots” need to be prepared of cells whose ultrastructure changes rapidly, for example muscle cells. A further disadvantage of manual manipulation of biopsy specimens is the fact that the gelatinous consistency and small dimensions of the tissue specimens considerably complicate reliable manual manipulation thereof, so that the reproducibility of the results is low and the reject rate is considerable. This in turn not only is undesirable for general cost reasons, but also is unacceptable especially in situations in which consideration must be given to the patient/examination subject or experimental animal, and excision of biopsy material therefore cannot be repeated an unlimited number of times, for example in the case of removal of specimens from a living myocardium. Lastly, the most important disadvantage of manual manipulation of biopsy specimens is the fact that this manipulation is so difficult to perform that, as indicated by experience, only a small percentage of the technical personnel of an institution are at all capable, even after extended training, of producing perfect or at least satisfactory specimens. The results of manual preparation are therefore poorly reproducible, and the user of commercial equipment must resort to employing, for preparation, persons who by fortunate accident possess manual and motor skills far above the average. 
     SUMMARY OF THE INVENTION 
     It was accordingly the object of the present invention greatly to increase the speed of the preparation operation (time requirement between excision and onset of freezing less than 30 seconds), and thereby to improve the quality of the snapshots of the specimens being examined. A further object of the invention was to improve the reliability and reproducibility of the preparation process as compared to manual preparation. Lastly, the further object presented was to decrease the manual and motor demands on implementing personnel, i.e. to facilitate working procedures for preparation and thereby to give even technical personnel of average training and skill the capability of producing perfect specimens. 
     The apparatus according to the present invention makes it possible greatly to increase the speed with which biopsy material is prepared: the time for a specimen removal operation, measured from insertion of the microbiopsy needle to completion of the initial freezing operation, is a maximum of 30 seconds. The reliability and reproducibility of preparation results has been considerably increased, and rejects have been practically entirely eliminated. Working procedures during preparation have been simplified, with the apparatus according to the present invention, in such a way that preparation can be reliably performed by technical personnel with average training and average manual skills. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the apparatus and its use will be presented by way of example below with reference to the drawings, the invention not being limited to these particular embodiments that are presented. The following components of the apparatus are depicted in the drawings, in perspective in each case: 
         FIGS. 1   a  and  1   b  show the two principles of biopsy transfer from the opening in the biopsy needle to the specimen well of the preparation plate; 
         FIGS. 2   a  through  2   f  show various embodiments of preparation plates; 
         FIG. 3  shows a transfer part; 
         FIG. 4  shows a slide with an inserted preparation plate, at an enlarged scale; 
         FIGS. 5 and 6  show two different embodiments of shifter parts, one of which is made up of several parts; 
         FIGS. 7 through 11  depict, by way of example, the various steps of the method for handling biopsy specimens using the method according to the present invention. In these Figures: 
         FIG. 7  shows a transfer part with an inserted slide and an empty preparation plate, as well as the inserted specimen holder in the ready position; 
         FIG. 8  shows a transfer part with a biopsy needle filled with the biopsy specimen; 
         FIG. 9  shows a transfer part with a biopsy needle and shifter part placed on it, and—indicated schematically with arrows—the motions necessary in order to transfer the biopsy from the biopsy needle into the preparation plate and the specimen holder; 
         FIGS. 10   a  through  10   g  show longitudinal sections through a transfer part with the various steps of transferring a biopsy specimen; and 
         FIGS. 11   a  through  11   e  show cross sections through a transfer part with the various steps of transferring a biopsy specimen. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The apparatus according to the present invention includes biopsy needles, only partially depicted in the FIGS., which have an opening for receiving the biopsy specimen that is substantially reduced in size compared to commercially obtainable products (for example, Pro-Mag™, Manan Medical Products, Inc., Northbrook, Ill. 60062, USA). The opening is, for example, 0.2–0.3 mm deep and only 1.2 mm long; this yields a volume for the resulting biopsies that corresponds to the volume of the specimen well of the preparation plate. The needle is permanently secured in the biopsy gun, so that the inner lance, with the opening for the biopsy material, is immovable with respect to the biopsy gun. 
       FIG. 1   a  shows two embodiments for transferring biopsy specimens using the apparatus according to the present invention. A biopsy specimen  3  is introduced into the empty opening  2  of a biopsy needle  1 . The needle filled with this biopsy specimen is centered on specimen well  4  of a preparation plate  5 . By advancing cylindrical shaped part  6  with its accurately fitting shaped tip  7 , the biopsy specimen is then transferred out of opening  2  into specimen well  4 . 
       FIG. 1   b  shows the manner in which a biopsy  3  can be transferred from opening  2  of biopsy needle  1  into specimen well  4  by means of a stream of fluid. A transition part  9  that connects syringe  8  and opening  2  is mounted onto a commercially obtainable injection syringe  8 . This transition part  9  has at the upper end a cavity for reception of injection syringe  8 ; at its lower end it is shaped in such a way that its cross section corresponds to the shape of opening  2  of biopsy needle  1 . By displacement of the piston of injection syringe  8 , the biopsy specimen is flushed by means of a stream of fluid (buffer solution, 1-hexadecene, etc.) into specimen well  4  of a preparation plate  5 . 
     Preparation plates  5 , depicted in  FIGS. 2   a  through  2   f  at enlarged size compared to the other Figures, are made of a material with good thermal conductivity—for example a metal, preferably from the series copper, brass, titanium, aluminum—and have a specimen well  4  that is embodied as a slot (in  FIG. 2   f  as a circular depression). Plates made of comparatively soft copper sheet, as used for example in the building trades, have proven particularly successful for this purpose. Other geometrical shapes are usable as an alternative to the circular shape of these preparation plates depicted in  FIG. 2 . In that case the shape of recess  22  of slide  21  ( FIG. 4 ) must be adapted accordingly. If shapes other than circles are used for preparation plates  5 , this offers the additional advantage that the geometrical orientation of preparation plate  5  and of specimen well  4  can be predetermined in accordance with recess  22  of slide  21 . Slot thickness b of specimen plate  5  emerges as a critical factor: it should not exceed 0.3 mm. If a &gt;2b, then b should not exceed 0.2 mm. For production-engineering reasons, specimen well  4  advantageously ends in a semicircle  10 , but other geometrical shapes are also permissible. The physical, thermal, and pressure-related properties of the preparation plates, and of the biological specimen being frozen, define the range of advisable dimensions. For the preparation plates proposed, these are a=0.3–5 mm, l=0.3–5 mm, and, as described above, b=0.2–0.3 mm. Diameter d must be at least l+0.6 mm, and should be no more than l+2 mm. In an exemplary embodiment, the preparation plates that are used have, for example, the following dimensions: a=0.6 mm, b=0.3 mm, l=1.2 mm, d=3 mm. The following morphological variants have proven useful: 
       FIG. 2   a : Metal disk having specimen well  4 . This shape offers the advantage that it can be manufactured easily and cheaply, but has the disadvantage that depending on the consistency of the specimen, the latter can be lost in some circumstances during transfer from the shifter part into the specimen holder. 
       FIGS. 2   b  and  2   c : Metal disks having a slot-shaped depression that extends only 0.05–0.1 mm onto the opposite side. The depression is cut through at center  11  ( FIG. 2   c ) or at both ends  12  ( FIG. 2   c ). This variant offers the advantage that the specimens cannot be lost during transfer. 
       FIGS. 2   d  and  2   e : Metal disks having the same geometry as  FIGS. 2   b  and  2   c , but fabricated from two permanently assembled parts. These variants are manufactured by fitting a plate according to  FIG. 2   a  to a metal foil  13  having corresponding holes  11  and  12 , for example by adhesive bonding with a suitable adhesive. 
       FIG. 2   f : This plate corresponds approximately to the plate of  FIG. 2   b . It contains a circular depression  14  rather than a slot-shaped one. This embodiment is not as good as plates  2   a  through  2   e  as regards freezing, but in terms of manufacture it is by far the most economical preparation plate variant. 
     The embodiment of a transfer part depicted by way of example in  FIG. 3  comprises a parallelepipedal shaped part  15  made of a material having a smooth surface and chemical resistance to the fluids used in freezing technology, for example 1-hexadecene, buffer solutions, carbohydrate solutions, etc. Metal alloys, in particular aluminum alloys, or plastics, for example POM, have proven successful as appropriate materials for this transfer part. This shaped part  15  has, on its upward-facing surface, a groove  16  extending through the entire length. Recessed into this groove is a second groove  17 , of defined length and position, for reception of a slide  21  and positioning thereof in groove  16 . Extending perpendicular to groove  16  is a deeper groove  18  that serves for reception and accurate positioning of a specimen holder  39  by means of hollow-cylindrical opening  19 , and for exact positioning of a shifter part  26  ( FIG. 5 ). The shorter part of groove  16  cut off by groove  18  is overlapped by a plate  20  permanently mounted on the upper side of shaped part  15 , in such a way that a defined cavity is created which makes possible accurate positioning of an introduced biopsy needle  1 . 
     The purpose of this transfer part  15  is to make preparation plates  5  available at the correct point for reception of biopsy specimens; then to receive the specimens in said preparation plates  5 ; and to transfer preparation plates  5 , filled with the specimens, into suitable specimen holders. 
     Slide  21  depicted at enlarged size in  FIG. 4  comprises a parallelepipedal strip of a suitable material, preferably the same material as shaped part  15  (for example, POM). It is dimensioned in such a way that it can easily be displaced manually in longitudinal groove  16  of shaped part  15 . This slide  21  has at one end a cut-out circular arc  22  of approx. 220°, which corresponds in its dimensions to the dimensions of a preparation plate  5  and can receive the latter for displacement within groove  16 . This recess  22  can also be of non-circular configuration, corresponding to the geometrical shape of preparation plate  5  that is used. The orientation of preparation plate  5  and of specimen well  4  in slide  21  can thereby be predetermined according to the user&#39;s wishes. This slide  21  furthermore has a vertical slot  23 , extending in the longitudinal axis, which enables biopsy specimen  3 , transferred into a preparation plate  5 , to be introduced into a suitable specimen holder  39 . Peg  24  on the underside of slide  21  serves to position slide  21  in groove  17 . Its end directed toward groove  18  defines the position for the transfer of biopsy specimen  3  from biopsy needle  1  into preparation plate  5 ; the other end defines the position of slide  21  in which preparation plate  5  can be secured in a suitable specimen holder  39 . Peg  25  serves as a handle for manual operation of slide  21 . 
     The shifter part is preferably produced from a transparent plastic that makes possible visual monitoring during the entire transfer operation of the biopsy specimen. In the embodiment shown in  FIG. 5 , this shifter part  26  is assembled from an upper part  27 , a lower part  31 , and several accessory parts. Upper part  27  is made up of two parallelepipedal shaped parts, and has a vertically extending, hollow-cylindrical orifice  28  and a horizontal slot  29 . Cylinder  6  (of  FIG. 1   a ) is inserted into orifice  28  of upper part  27  and is permanently joined to shaped part  27 . Cylinder  6  has a tip  7  which corresponds in its base outline to opening  2  of a biopsy needle, and is placed asymmetrically on the underside of cylinder  6 . 
     Upon assembly of the shifter part from the upper and lower parts, a short helical spring  36  is first placed around the portion of cylinder  6  projecting out of upper part  27 . Cylinder  6  is then introduced through orifice  33  into lower part  31 , and remains freely movable in said orifice. 
     Shaped part  27  of the upper part is then movably joined to shaped part  31  of the lower part by means of a screw  30  which is screwed into place, through a slot  29  extending horizontally through said upper part, in a horizontally extending screw thread  32  of lower part  31 . Foot  34  of shaped part  31  in turn engages into groove  18  of transfer part  15 , and allows the assembled shifter part  26  to be displaced in controlled fashion, as a unit, in said groove  18 . 
     Extending on the underside of shaped part  31  which contains orifice  33  is a step  35  whose height corresponds to the diameter of a biopsy needle. This step  35  serves to clamp biopsy needle  1 , which initially is laid loosely against the lateral surface of plate  20  ( FIG. 3 ), in place between step  35  and said lateral surface of plate  20 , and thereby to position it at the desired point above preparation plate  5 . As an alternative to this, biopsy needle  1  can be introduced into a previously prepared cavity above preparation plate  5 . A cavity of this kind can be constituted, for example, by the fact that shaped part  31  is first slid against frame  40  (inserted into opening  19 ) of sample holder  39 , so that step  35  forms, with the lateral surface of plate  20 , an accurately fitted cavity for biopsy needle  1 . 
     Vertical displacement of parts  27  and  31  with respect to one another causes the transfer of biopsy specimen  3  from biopsy needle  1  into preparation plate  5 , as was depicted in  FIG. 1   a.    
     As an alternative to this embodiment assembled from multiple parts, an embodiment of a shifter part as shown in  FIG. 6 , made up of a single part, can be used. This serves to transfer mechanically sensitive biopsy specimens into preparation plate  5  by means of a stream of fluid, rather than by the action of a solid cylinder  6 . This embodiment comprises a shaped part  37  which has a vertically extending hollow-cylindrical orifice  38 . The shape of this orifice  38  corresponds to that of transition part  9  of  FIG. 1   b , and serves to receive injection syringe  8  during flushing of a biopsy specimen  3  out of biopsy needle  1  into a preparation plate  5 . This shaped part  37  also has on its underside a step  35  which serves, together with plate  20 , to clamp biopsy needle  1  in place and which, in the manner already described, contributes to the formation of a cavity into which biopsy needle  1  can subsequently be inserted. 
     This one-piece shifter part  37  serves for the transfer of mechanically sensitive specimens, e.g. brain tissue specimens. In this method, the excess flushing fluid leaves the apparatus through the two grooves  16  and  18 . 
     The method for using the apparatus according to the present invention is depicted in  FIGS. 7 through 9 . 
     In a first method step, specimen holder  39  is inserted into groove  16  and into opening  19  of transfer part  15  ( FIG. 7 ). A product designed for a high-pressure freezing unit (Product Bulletin 16 50 02 of December 2000, of Leica Microsystems GmbH (Leica EM PACT)) serves, for example as the specimen holder. This specimen holder  39  comprises the following individual parts: A casing  40  serves as a mechanical frame for reception of the other components. Inserted in a corresponding screw thread in the longitudinal axis of said frame  40  is a screw  41  which has a diamond sealing surface  42  at its end protruding into the frame, and which serves to clamp preparation plate  5  securely in place. Provided on the side of frame  40  opposite the screw thread is a support apparatus  43  for preparation plate  5 , which in turn is connected to the pressure line for transferring high pressure during the freezing operation. Extensions  44  and  45  of frame  40 , configured as hollow cylinders, serve to anchor the specimen holder in the high-pressure freezing unit; extension  45  additionally immobilizes the specimen holder in accurately fitting fashion in opening  19  of transfer part  15  during transfer of the biopsy specimens. 
     Slide  21  with the empty preparation plate  5  is then inserted into groove  16  of transfer part  15  so that peg  24  comes to a stop against the outer edge of transfer part  15  (position I in  FIG. 10   b ), and an empty preparation plate  5  is placed into recess  22 . Slide  21  with the empty preparation plate  5  is then slid into said groove  16  until peg  24  comes to a stop against the end of depression  17  adjacent to groove  18  (position II in  FIGS. 10   b  and  10   c ). Preparation plate  5  is now in a defined position and is ready for reception of a biopsy specimen. 
     The biopsy is then taken from the tissue using a commercially obtainable microbiopsy apparatus. If an opening in the lance of the biopsy needle which is smaller than in the methods previously described is used, it has been found that upon insertion of the needle into the tissue, the tip and opening of the lance are usefully immovably positioned in front of the cutting edge of the hollow needle. As a result, and in contrast to the methods previously described (Hohenberg op. cit. p. 135), the opening can be positioned very accurately in the tissue. Because of the relatively slow advance of the lance, in contrast to the commercially obtainable apparatuses the tissue can fill the opening of the lance better and more easily. In order to cut off the tissue that has entered the small opening in this fashion, the hollow needle is slid over the lance in a manner known per se. The needle is then pulled out of the tissue, and biopsy specimen  3  is exposed again by pulling the hollow needle back. 
     With a predetermined insertion depth along the lateral surface of plate  20 , biopsy specimen  3  in opening  2  of biopsy needle  1  comes to rest exactly above specimen well  4  of a preparation plate  5 , as depicted in  FIG. 8 . Shifter part  26  or  37  (only shifter part  26  is depicted in  FIG. 9 ) is then introduced into groove  18  of transfer part  15  and displaced into it until step  35  on the underside of shaped part  31  presses biopsy needle  1  against the lateral surface of plate  20  and clamps it in place. As a result, opening  2  of biopsy needle  1  is positioned exactly above specimen well  4  of preparation plate  5  prepared for it. 
     Transfer of a biopsy specimen  3  from biopsy needle  1  into specimen plate  5  and then into specimen holder  39  is depicted in  FIGS. 10   a  through 10g (longitudinal section through the center of groove  18 ). 
     In order to insert preparation plate  5  into slide  21 , slide  21  is positioned in groove  16  at the end facing away from groove  18 . Peg  24  protrudes beyond the upper edge of transfer part  15  (position I) ( FIG. 10   a ). 
     Specimen holder  39  is then inserted into groove  18  and opening  19  ( FIG. 10   b ). 
     Slide  21  is displaced as far as the stop (position II) of peg  24  located closer to specimen holder  39 , so that preparation plate  5  lies partially beneath plate  20  (not depicted). Biopsy needle  1  filled with a biopsy specimen  3  is then laid loosely against the lateral surface of plate  20 , so that biopsy specimen  3  lies exactly above specimen well  4  of preparation plate  5 . The correct position of biopsy specimen  3  in the longitudinal axis of groove  16  is defined by guiding the biopsy gun (not depicted in the Figure), in which biopsy needle  1  is mounted, as far as a predetermined stop on the apparatus, for example against the outer edge of a base plate (not depicted in the Figure) ( FIG. 10   c ). As an alternative thereto, this position of biopsy needle  1  in the longitudinal axis of groove  16  can also be defined by guiding its tip as far as a predefined stop, for example in shaped part  31  or on the lateral wall of specimen holder  39 . 
     Displacement of shifter part  31  or  37  in groove  18  to the point of contact against the lateral surface of frame  40  of specimen holder  39  causes biopsy needle  1  with biopsy specimen  3  to be secured between the shifter part and the lateral surface of plate  20 . As an alternative thereto, biopsy needle  1  can also be introduced into a previously prepared cavity. A cavity of this kind can be formed, for example, in such a way that the last two method steps are transposed: after the positioning of preparation plate  5  in position II, the shifter part is inserted into groove  18  and displaced until the lateral surface of shaped part  31  or  37  is resting against the lateral surface of frame  40  of specimen holder  39 . Biopsy needle  1  is then introduced into the cavity thereby formed between groove  18 , the lateral surface of  31  or  37 , and the lateral surface of plate  20 . Biopsy specimen  3  is then pushed, by a vertical motion of cylinder  6 , from biopsy needle  1  into specimen plate  5  ( FIG. 10   d ). 
     Slide  21  is next displaced to the opposite stop of peg  24  in depression  17  (position III). Preparation plate  5  filled with biopsy specimen  3  is thereby correctly positioned in specimen holder  39  and clamped in place by means of screw  41  ( FIG. 10   e ). 
     Lastly, slide  21  is pulled back into its starting position at the farther end of groove  16 , and peg  24  is displaced back out of position III into its starting position I on the outer edge of transfer part  15  ( FIGS. 10   f  and  10   g ). Specimen holder  39 , with preparation plate  5  clamped in place, is then secured in a manipulator which allows removal from groove  18  and opening  19 , and freezing of the biopsy specimen. 
       FIGS. 11   a  through  11   e  depict the introduction of biopsy needle  1  and the transfer of biopsy specimen  3  from biopsy needle  1  into preparation plate  5 , in a cross section through a transfer part  15  and through an embodiment of a shifter part made up of the two shaped parts  27  and  31 . 
     Biopsy needle  1  is laid in the predetermined position, perpendicular to the plane of the drawing, against the lateral surface of plate  20 , which is permanently mounted on the upper side of shaped part  15  and in turn partially overlaps preparation plate  5  ( FIG. 11   a ). 
     In order to immobilize biopsy needle  1 , the shifter part made up of the two shaped parts  27  and  31  is introduced into groove  18  and is pushed farther in the direction of biopsy needle  1  until the cut-out step  35  on the underside of shaped part  31  comes to a stop against biopsy needle  1 . As a result, the latter is clamped in place between step  35 , the lateral surface of plate  20 , and preparation plate  5 , and is immobilized in that position. Tip  7  of cylinder  6  is now located vertically above opening  2 , filled with biopsy specimen  3 , of biopsy needle  1  ( FIG. 11   b ). 
     As an alternative thereto, biopsy needle  1  can also be introduced into a previously prepared cavity. A cavity of this kind can be formed, for example, in such a way that the last two method steps are transposed: After the positioning of preparation plate  5  in position II, shifter part is inserted into groove  18  and displaced until the lateral surface of shaped part  31  or  37  is resting against the lateral surface of frame  40  of specimen holder  39 . Biopsy needle  1  is then introduced into the cavity thereby formed between groove  18 , the lateral surface of  31  or  37 , and the lateral surface of plate  20 . 
     Shaped part  27 , with cylinder  6 , is then displaced by hand vertically downward in arrow direction A-A as depicted. As a result of this vertical motion, tip  7  of cylinder  6  pushes biopsy specimen  3  out of opening  2  of biopsy needle  1  into depression  4  of the prepared preparation plate  5 . This vertical motion requires that the spring force of helical spring  36 , placed between shaped parts  27  and  31 , be overcome ( FIG. 11   c ). 
     When the force exerted on shaped part  27  is then released, cylinder  6  is pushed back into its starting position by the spring force of helical spring  36 . As a result, the empty biopsy needle  1  is once again movable in its longitudinal axis and can be pulled back ( FIG. 11   d ). 
     Lastly, shifter part  26  made up of the two shaped parts  27  and  31  is ideally rotated about its longitudinal axis and thereby removed from transfer part  15 . The preparation plate filled with biopsy specimen  3  can now be displaced in the direction of specimen holder  39  and clamped in place therein. The underside of shaped part  31 , and tip  7  of cylinder  6 , are cleaned, and are available for the next specimen transfer ( FIG. 11   e ).