METHOD FOR PREPARING A SAMPLER ARRANGEMENT, METHOD FOR PRODUCEING A DISSECT, KIT AND SAMPLER ARRANGEMENT

Description

Technical field

[0001] The invention relates to a method for preparing a sample carrier arrangement for use in a laser microdissection device and a method for producing a dissectate. The invention further relates to a kit for carrying out such methods and a sample carrier arrangement. background

[0002] Cryo-electron microscopy is a form of electron microscopy used to examine biological samples. In particular, cryo-electron microscopy enables high-resolution structural analysis of biological molecules, such as proteins. Special sample carriers are used to observe samples in an electron microscope. These electron microscope sample carriers consist of a grid, also called an EM grid, and a thin support layer arranged on the grid, upon which the samples to be observed rest. To biochemically analyze individual samples or specific parts of a sample following electron microscopy, they must be removed from the electron microscope sample carrier. This can be done, for example, using laser microdissection. The removed sample components are called dissectates.The samples and the underlying support layer are dissected using laser light to generate the dissectants. However, it is not readily possible to use the electron microscope specimen holder in a laser microdissection device. The dissectants remain adhered to the electron microscope specimen holder, particularly due to electrostatic attraction, or are strongly attracted to it after dissection, making transfer to a collection container impossible.

[0003] From Application Note: "Adhesives for TEM Sample Preparation", dated June 1, 2020 (2020-06-01), XP093264736, a mixture (M-Bond) of a polymer (epoxide) and a solvent (phenol) for a TEM grating is known. The document is available at https: / / www.alliedhightech.com / Media / Default / ProductcY020Usec / 0201nstructions / ApplicationscY020Note / 020- / 020Adhesives%20for / 020TE IVP / 020Sample / 020Preparation,v1.0.pdf

[0004] The object of the present invention is therefore to provide a method, a kit and a sample carrier arrangement that allows dissectates to be obtained from an electron microscope sample carrier using a laser microdissection device. Overview

[0005] The proposed method for preparing a sample support assembly for use in a laser microdissection device involves providing an electron microscope sample support comprising a grid and a support layer for carrying a sample positioned on one side of the grid. A mixture of a polymer and a solvent is applied to the side of the grid facing away from the support layer. At least some of the solvent is then evaporated, causing the polymer to harden and form the sample support assembly.

[0006] The grid is also known as an electron microscope grid or EM grid. The grid is typically circular and has a diameter ranging from 3.00 mm to 3.05 mm. The mesh size can range from 0.025 µm to 450 µm. The grid is typically made of a metal, such as copper, gold, molybdenum, nickel, aluminum, titanium, or stainless steel. The support layer is typically a thin layer with a thickness ranging from 300 µm to 500 µm. The support layer is typically made of amorphous carbon or graphene.

[0007] In the proposed method, a very thin film of the polymer-solvent mixture is applied to the side of the electron microscope slide facing away from the sample. At least some of the solvent evaporates, causing the polymer to harden and forming a thin layer of polymer on the side of the slide facing away from the sample. This thin layer of polymer increases the mass of the dissectants obtained when the slide is processed with the laser microdissection device. This allows the dissectants to overcome the electrostatic attraction between themselves and the rest of the slide. This facilitates the transfer of the dissectants from the slide to, for example, a collection vessel.The proposed method thus makes it possible to prepare the electron microscope sample carriers in such a way that dissections can be extracted from them using the laser microdissection device.

[0008] In one embodiment, a laser microdissection specimen holder is provided, comprising a membrane configured to be cut by the laser microdissection device. The mixture is applied to the membrane of the laser microdissection specimen holder. The electron microscope specimen holder is positioned on the membrane of the laser microdissection specimen holder such that the membrane, the mixture, the grid, and the support layer are arranged one above the other in that order. Furthermore, at least some of the solvent is evaporated, causing the polymer to harden and form the specimen holder assembly. The evaporation of the solvent creates a thin layer of the polymer between the membrane of the laser microdissection specimen holder and the electron microscope specimen holder, bonding the two elements together.Dissections obtained during processing of the sample carrier assembly with the laser microdissection device consequently comprise a portion of the membrane. In this embodiment of the method, a sample carrier assembly is obtained that includes the electron microscope sample carrier mounted on the laser microdissection sample carrier. The sample carrier assembly thus obtained is particularly easy to handle.

[0009] In an alternative embodiment, a laser microdissection specimen carrier is provided, comprising a membrane designed to be cut by the laser microdissection device. An opening is created in the membrane, the diameter of which is smaller than the diameter of the electron microscope specimen carrier. Furthermore, the electron microscope specimen carrier, with the polymer applied and cured thereon, is positioned on the membrane such that the specimen carrier assembly is located above the opening in the membrane and that the support layer is arranged on the side of the grid facing away from the membrane. The opening in the membrane is preferably round and has a diameter of 1.0 mm to 3.0 mm. In this embodiment of the method, a specimen carrier assembly is also obtained, comprising the electron microscope specimen carrier arranged on the laser microdissection specimen carrier.However, in this embodiment, the electron microscope sample holder is not necessarily fixed to the laser microdissection sample holder. Dissects obtained during processing of the sample holder assembly with the laser microdissection device therefore do not include any part of the membrane, which can be advantageous for certain applications.

[0010] The invention further relates to a method for producing a dissectate, in which the sample carrier assembly is prepared for use in the laser microdissection device using the method described above. Furthermore, the dissectate, comprising at least the sample, a portion of the support layer, and a portion of the cured polymer, is produced from the sample carrier assembly using the laser microdissection device. The dissectate is, in particular, separated from the surrounding sample by cutting the sample carrier assembly with the laser microdissection device. The method particularly includes a further process step in which the dissectate is removed from the remainder of the sample carrier assembly. The removal of the dissectate is, in particular, carried out by means of gravity. The produced dissectate falls, for example, into a collection vessel arranged below the sample carrier assembly.Alternatively, the dissected specimen can also be catapulted away from the sample holder, for example using a defocused laser pulse. The dissected specimen can then be catapulted, for instance, in the direction of gravity into a collection vessel or against gravity onto a preferably adhesive receptacle.

[0011] The proposed methods can be further developed, in particular, with the features described below in the claims relating to a kit and a sample carrier arrangement. Conversely, the kit and the sample carrier arrangement can also be further developed with features in the claims relating to the methods.

[0012] The invention also relates to a kit for carrying out the methods described above. The kit comprises an electron microscope sample holder, which includes a grid and a support layer for carrying a sample arranged on one side of the grid, and a mixture of a polymer and a solvent. The kit has the same advantages as the methods described above.

[0013] In one embodiment, the mixture comprises between 20 and 90% by volume of the solvent, preferably between 50 and 90% by volume. The higher the proportion of solvent in the mixture, the more viscous the mixture. A thinner mixture allows for the formation of a thinner film on the side of the electron microscope slide facing away from the sample. Upon evaporation, this thinner film of the polymer is formed, which is easier to section using the laser microdissection device.

[0014] It was found that a solvent concentration of between 50 and 90% by volume is optimal for producing a polymer layer that is easy to cut.

[0015] In another embodiment, the mixture comprises between 20 and 80% by volume of the polymer, preferably between 20 and 50% by volume. The higher the proportion of polymer in the mixture, the more viscous the mixture. To produce the thinnest possible polymer layer, which is therefore easy to cut, a proportion of between 20 and 50% by volume of polymer is optimal.

[0016] In another embodiment, the mixture comprises at least one of the following substances as the polymer: a polystyrene, a polyacrylate, and a silicone. The aforementioned polymers are widely available and easy to produce, making the kit particularly cost-effective. Furthermore, these polymers are especially suitable for use with biological samples because they are non-toxic or only slightly toxic.

[0017] In another embodiment, the mixture comprises xylene as the solvent. The mixture can also include other solvents, such as toluene, and mixtures of solvents. Xylene is a solvent that can reliably dissolve a wide variety of polymers. This makes the kit highly versatile.

[0018] The kit comprises a laser microdissection specimen holder with a membrane designed to be sectioned by a laser microdissection device. The membrane is made of polyethylene naphthalate (PEN), polyethylene tetraphyllite (PET), polyphenylene sulfite (PPS), polyester (POL), or polyetherimide (PEI). This embodiment of the kit allows the user to pre-assemble the specimen holder assembly on the laser microdissection specimen holder, making the assembly particularly easy to handle.

[0019] In another embodiment, the laser microdissection specimen holder comprises a frame with an opening through the frame. The membrane is arranged in the opening of the frame. The frame can be made of metal or plastic and is particularly likely to be a single piece. In this embodiment, the membrane is, for example, clamped into the frame or adhered to the frame in such a way that the membrane spans the opening of the frame. The user can grasp the laser microdissection specimen holder, and thus the specimen holder assembly, by the frame without damaging the membrane. The specimen holder assembly prepared using the kit according to this embodiment is therefore particularly easy to handle.

[0020] In an alternative embodiment, the laser microdissection specimen holder comprises a support plate, in particular a support plate made of glass. A recess is arranged in the support plate. The membrane spans the recess in the support plate, so that a space is formed between the support plate and the membrane.

[0021] The membrane has an opening whose diameter is smaller than that of the electron microscope specimen holder. This opening allows the user to prepare the specimen holder assembly so that, when processed with the laser microdissection device, a dissected specimen is produced that does not include any part of the membrane.

[0022] Alternatively, in addition to the cut-out membranes, a pre-made holding frame with an opening smaller than the diameter of the electron microscope sample holder can also be used.

[0023] The invention further relates to a sample carrier arrangement for use in a laser microdissection device, comprising an electron microscope sample carrier that includes a grid and a thin support layer for carrying a sample arranged on one side of the grid. A mixture of a polymer and a solvent is applied to the side of the grid facing away from the support layer. The sample carrier arrangement has the same advantages as the method and kit described above and can be further developed, in particular, with the features of the claims directed to the kit. Conversely, the kit can also be further developed with the features of the claims directed to the sample carrier arrangement.

[0024] In one embodiment, the sample carrier assembly comprises a membrane configured to be cut by a laser microdissection device, with the mixture positioned between the grid and the membrane. The sample carrier assembly may further comprise a laser microdissection sample carrier encompassing the membrane. In such an embodiment, the electron microscope sample carrier is positioned on the membrane of the laser microdissection sample carrier. This allows the user to easily handle the sample carrier assembly. In particular, some of the solvent may have evaporated, causing the polymer to harden and forming a layer of the polymer between the electron microscope sample carrier and the membrane. This layer bonds the electron microscope sample carrier and the membrane.

[0025] In one embodiment, the sample carrier assembly comprises a laser microdissection sample carrier with a membrane configured to be cut by a laser microdissection device. The membrane has an opening whose diameter is smaller than the diameter of the electron microscope sample carrier. The electron microscope sample carrier is positioned on the opening of the membrane such that the mixture is located on the side of the grid facing the membrane, and the support layer is located on the side of the grid facing away from the membrane. At least some of the solvent has evaporated, so that the polymer has hardened. The sample carrier according to this embodiment can be processed with the laser microdissection device, resulting in a dissected portion that does not include any part of the membrane.

[0026] Further features and advantages will become apparent from the following description, which, in conjunction with the attached figures, explains exemplary embodiments in more detail. Brief description of the characters

[0027] They show: Figure 1 shows a sample holder arrangement for use in a laser microdissection device according to an exemplary embodiment; Figure 2 shows a section through the sample holder arrangement according to Figure 1 Figure 3 shows a dissection obtained from the sample carrier arrangement according to the Figure 1 and 2 was obtained; Figures 4a to 4c each show a process step of a process for preparing the sample carrier arrangement according to the Figure 1 and 2 for use in the laser microdissection device; Figure 5 a section through a sample carrier arrangement according to a further embodiment; Figure 6 a dissected specimen obtained from the sample carrier arrangement according to Figure 5was obtained; Figures 7a to 7c each show a process step of a procedure for preparing the sample carrier arrangement according to Figure 5 for use in the laser microdissection device; and Figure 8 a section through the specimen carrier arrangement according to the prior art. Description

[0028] Figure 1 Figure 1 shows a schematic perspective representation of a sample carrier arrangement 100 for use in a laser microdissection device according to an exemplary embodiment.

[0029] The sample carrier arrangement 100 comprises a laser microdissection sample carrier 102 and an electron microscope sample carrier 104, which is arranged on the laser microdissection sample carrier 102. A detailed view in Figure 1 shows an area of ​​the laser microdissection specimen holder 102 on which the electron microscope specimen holder 104 is arranged.

[0030] The laser microdissection specimen holder 102 comprises a frame 106 and a membrane 108. The frame 106 is, by way of example, made of a metal and has an opening through which the membrane 108 is arranged. The membrane 108 can, for example, be clamped in the frame 106 or adhered to the frame 106 in such a way that the membrane 108 completely covers the opening of the frame 106. The membrane 108 is, in particular, a membrane 108 made of PEN and designed to be cut with the laser microdissection device.

[0031] The electron microscope sample holder 104 comprises a grid 110, also called an EM grid or TEM grid, and a support layer 112 for supporting samples 114, which is arranged on the grid 110. The grid 110 is preferably made of a metal and typically has a diameter of 3.00 mm or 3.05 mm. The mesh size of the grid 110 is selected such that the electron beam of a transmission electron microscope can pass through the grid 110 without interfering with the flow. Typically, the mesh size is specified in the unit mesh, which indicates the number of holes per square inch. Typical electron microscope sample holders 104 have 50 to 600 meshes, which corresponds approximately to a mesh diameter in the range of 0.025 µm to 450 µm. The support layer 112 is a thin layer with a thickness in the range of 300 Å to 500 Å, which prevents the samples 114 from falling through the mesh of the grid 110.The support layer 112 is made in particular of carbon, for example amorphous carbon or graphene.

[0032] A layer 116 of a polymer is arranged between the laser microdissection specimen holder 102 and the electron microscope specimen holder 104. The polymer layer 116 connects the electron microscope specimen holder 104 to the membrane 108 of the laser microdissection specimen holder 102. To obtain the polymer layer 116, a mixture 400 (see Figure 4 ) from the polymer and a solvent between the membrane 108 and the electron microscope sample holder 104. Furthermore, at least some of the solvent was evaporated to obtain the polymer layer 116. This method for preparing the sample holder assembly 100 for use in the laser microdissection device is described below with reference to the Figures 4a to 4c described in more detail.

[0033] Figure 2shows a schematic representation of a cross-section through the sample carrier arrangement 100 according to Figure 1 .

[0034] The sample carrier assembly 100 comprises several layers arranged one above the other. The thickness of the layers shown is not to scale. The bottom layer is formed by the membrane 108 of the laser microdissection sample carrier 102. Above this is the polymer layer 116. Above the polymer layer 116 is the grid 110. Finally, on top of the grid 110 is the support layer 112, which carries the samples 114.

[0035] To obtain a dissection 300 from the sample carrier arrangement 100 (see Figure 3To obtain the sample carrier assembly 100, the sample carrier assembly 100 is processed using the laser microdissection device. In particular, one of the samples 114 is cut out of the sample carrier assembly 100 using a focused laser beam. Alternatively, the dissected part 300 can also be obtained by tearing it out. The dissected part 300 thus obtained is then separated from the rest of the sample carrier assembly 100. For example, the dissected part 300 falls into a collection vessel located below the sample carrier assembly 100 due to gravity. Alternatively, the dissected part 300 can also be catapulted away from the rest of the sample carrier assembly 100 using a defocused laser beam. An exemplary dissected part 300 is shown in the Figure 3 described.

[0036] Figure 3 The schematic representation shows a dissection 300, which is taken from the sample carrier arrangement 100 according to the Figure 1 and 2 was received.

[0037] The dissectate 300 comprises one of the samples 114, a portion 302 of the support layer 112, a portion 304 of the polymer layer 116, and a portion 306 of the membrane 108. The portion 302 of the polymer layer 116 increases the mass of the dissectate 300 compared to a dissectate without the polymer layer 116. This allows the dissectate 300 to overcome the electrostatic attraction between itself and the rest of the sample carrier assembly 100 and to separate from the rest of the sample carrier assembly 100. The electrostatic attraction between a dissectate, for example, a particle, a protein conglomerate, a single cell, or a bacterium, and the rest of a known sample carrier assembly 800 is described by the Figure 8 described in more detail below.

[0038] The Figures 4a to 4c Illustrate the procedure for preparing the sample carrier arrangement 100 for use in the laser microdissection device.

[0039] In the one based on the Figures 4a to 4cThe described procedure involves preparing a sample carrier according to the Figure 1 and 2 The first step in the process involves providing the electron microscope sample holder 104 and the laser microdissection sample holder 102. The mixture 400, consisting of the polymer and the solvent, is also provided. Mixture 400 comprises, for example, 20% by volume of the polymer and 80% by volume of the solvent. The polymer is, purely by way of example, polystyrene, and the solvent is, purely by way of example, xylene.

[0040] In the based on the Figure 4a In the illustrated process step, the mixture 400 is applied to the membrane 108 of the laser microdissection specimen carrier 102. Preferably, the mixture 400 is applied centrally to the membrane 108. In the step illustrated above, Figure 4bIn the illustrated process step, the electron microscope sample holder 104 with the samples 114 is now applied to the membrane 108 such that the mixture 400 is arranged between the membrane 108 and the electron microscope sample holder 104 and that the samples 114 are arranged on the side of the electron microscope sample holder 104 facing away from the membrane 108. In the last process step, which is illustrated by the Figure 4c As illustrated, at least some of the solvent evaporates. This causes the polymer to harden, forming the polymer layer 116 between the membrane 108 and the electron microscope sample holder 104.

[0041] Figure 5 Figure 5 shows a schematic representation of a section through a sample carrier arrangement 500 according to a further embodiment.

[0042] The sample carrier arrangement 500 according to the Figure 5 differs from the sample carrier arrangement 500 according to the Figure 1 and 2in that the membrane 108 of the laser microdissection specimen holder 102 has an opening 502. The diameter of the opening 502 is smaller than the diameter of the electron microscope specimen holder 104. The electron microscope specimen holder 104 is positioned over the opening 502 such that the specimens 114 are located on the side of the electron microscope specimen holder 104 facing away from the opening 502. When the specimen holder assembly 500 is processed with the laser microdissection device, a dissectate 600 is obtained that does not include any part of the membrane 108. An exemplary dissectate 600 is described below with reference to the Figure 6 A method for preparing the sample carrier arrangement 500 for use in the laser microdissection device is described in more detail below with reference to Figures 7a to 7d.

[0043] Figure 6 The schematic representation shows a dissection 600, which is taken from the sample carrier arrangement 500. Figure 5 was received.

[0044] The dissection 600 comprises one of the samples 114, a part 602 of the support layer 112 and a part 604 of the polymer layer 116. Unlike the one based on the Figure 3 The dissection 300 described comprises the one in Figure 5 The dissectate 500 shown does not include part 306 of the membrane 108. In this dissectate 300 as well, part 604 of the polymer layer 116 increases the mass of the dissectate 600, and the dissectate 600 can overcome the electrostatic attraction between the dissectate 600 and the rest of the sample carrier arrangement 500 in order to be separated from the rest of the sample carrier arrangement 500.

[0045] The Figures 7a to 7c Illustrate the procedure for preparing the sample carrier arrangement 500 for use in the laser microdissection device.

[0046] In the one based on the Figures 7a to 7c The described procedure uses a sample carrier according to Figure 5received. As a first procedural step, the electron microscope sample holder 104 and the laser microdissection sample holder 102 are provided.

[0047] In the based on the Figure 7a In the illustrated process step, the opening 502 is created in the membrane 108. This can be done, for example, using the laser microdissection device. The diameter of the opening 502 must be smaller than the diameter of the electron microscope sample holder 104. If the diameter of the electron microscope sample holder 104 is 3.00 mm, the opening 502 preferably has a diameter of 1.0 mm to 2.90 mm. If the diameter of the electron microscope sample holder 104 is 3.05 mm, the opening 502 preferably has a diameter of 1.0 mm to 3.00 mm. In the process shown, Figure 7bIn the illustrated process step, the mixture 400 is applied to the side of the electron microscope sample holder 104 facing away from the samples 114. At least some of the solvent is then evaporated to harden the polymer and obtain the polymer layer 116. In the final process step, the electron microscope sample holder 104 with the polymer layer 116 is then positioned on the opening 502 of the laser microdissection sample holder 102 to obtain the sample holder assembly 500. The final process step is illustrated by the Figure 7c illustrated.

[0048] Figure 8 The schematic representation shows a cross-section through the sample carrier arrangement 800 according to the state of the art.

[0049] The known sample carrier arrangement 800 consists of an electron microscope sample carrier 804, which is arranged on a membrane 808 of a laser microdissection sample carrier 802. The electron microscope sample carrier 804 is positioned over an opening 806 in the membrane 808. Dissections 810 cut from the electron microscope sample carrier 804 initially fall out of the electron microscope sample carrier 804. However, the electrostatic attraction between the dissections 810 and the rest of the electron microscope sample carrier 804 ensures that the dissections 810 adhere to the underside of the electron microscope sample carrier 804.

[0050] The term "and / or" encompasses all combinations of one or more of the associated listed elements and can be abbreviated with " / ".

[0051] Although some aspects have been described within the context of a device, it is clear that these aspects also constitute a description of the corresponding process, where a block or device corresponds to a process step or a function of a process step. Similarly, aspects described within the context of a process step also constitute a description of a corresponding block or element or property of a corresponding device. Reference symbol list

[0052] 100 Sample holder assembly 102 Laser microdissection sample holder 104 Electron microscope sample holder 106 Frame 108 Membrane 110 Grid 112 Support layer 114 Samples 116 Polymer layer 300 Dissectate 302, 304, 306 Part 400 Mixture 500 Sample holder assembly 502 Aperture 602, 604 Part 800 Sample holder assembly 802 Laser microdissection sample holder 804 Electron microscope sample holder 806 Aperture 808 Membrane 810 Dissectate

Claims

1. Method for preparing a sample holder assembly (100, 500) for use in a laser microdissection device, wherein an electron microscope sample carrier (104) is provided, which comprises a grid (110) and a support layer (112) for carrying a sample (114), which is disposed on one side of the grid (110); on the side of the grid (110) that is facing away from the support layer (112), a mixture (400) of a polymer and a solvent is applied; and at least part of the solvent is evaporated, so that the polymer cures, in order to obtain the sample holder assembly (100, 500).

2. Method according to claim 1, wherein a laser microdissection sample carrier (102) is provided, which comprises a membrane (108), which is configured to be cut by the laser microdissection device; the mixture (400) is applied to the membrane (108) of the laser microdissection sample carrier (102); the electron microscope sample carrier (104) is disposed on the membrane (108) of the laser microdissection sample carrier (102) in such a way that the membrane (108), the mixture (400), the grid (110) and the support layer (112) are disposed one above the other in this order; and at least part of the solvent is evaporated, so that the polymer cures, in order to obtain the sample holder assembly (100).

3. Method according to claim 1, wherein a laser microdissection sample carrier (102) is provided, which comprises a membrane (108), which is configured to be cut by the laser microdissection device; an opening is produced in the membrane (108), the diameter of which is smaller than the diameter of the electron microscope sample carrier (104); and the electron microscope sample carrier (104) with the polymer applied and cured thereon is disposed on the membrane (108) in such a way that the sample holder assembly (100, 500) is disposed above the opening in the membrane (108) and that the support layer (112) is disposed on the side of the grid (110) facing away from the membrane (108), in order to obtain the sample holder assembly (500).

4. Method for producing a dissectate (300), wherein, using the method according to one of claims 1 to 3, the sample holder assembly (100, 500) is prepared for use in the laser microdissection device; and wherein, using the laser microdissection device, the dissectate (300), which comprises at least the sample (114), a part (302, 602) of the support layer (112) and a part (306, 604) of the cured polymer, is produced from the sample holder assembly (100, 500).

5. Kit for carrying out a method according to one of claims 1 to 4, with an electron microscope sample carrier (104), which comprises a grid (110) and a support layer (112) for carrying a sample (114), which is disposed on one side of the grid (110); a laser microdissection sample carrier (102) with a membrane (108), which is configured to be cut by a laser microdissection device, wherein the membrane (108) has an opening (502), the diameter of which is smaller than the diameter of the electron microscope sample carrier (104); and a mixture (400) of a polymer and a solvent.

6. A kit according to claim 5, wherein the mixture (400) comprises between 20 and 90 volume-% of the solvent, preferably between 50 and 90 volume-% of the solvent.

7. Kit according to claim 5 or 6, wherein the mixture (400) comprises between 20 and 80 volume-% of the polymer, preferably between 20 and 50 volume-% of the polymer.

8. Kit according to one of claims 5 to 7, wherein the mixture (400) comprises at least one of the following substances as the polymer: a polystyrene, a polyacrylate and a silicone.

9. Kit according to one of claims 5 to 8, wherein the mixture (400) comprises xylene as the solvent.

10. Kit according to one of claims 5 to 9, wherein the laser microdissection sample carrier (102) comprises a frame (106) with an opening extending through the frame (106) and the membrane (108) is disposed in the opening of the frame (106).

11. sample holder assembly (100, 500) for use in a laser microdissection device, with an electron microscope sample carrier (104), which comprises a grid (110) and a thin support layer (112) for carrying a sample (114), which is disposed on one side of the grid (110), wherein a mixture (400) of a polymer and a solvent is applied on the side of the grid (110) facing away from the support layer (112).

12. sample holder assembly (100) according to claim 11, comprising a membrane (108), which is configured to be cut by a laser microdissection device, wherein the mixture (400) is disposed between the grid (110) and the membrane (108).

13. sample holder assembly (500) according to claim 11, comprising a laser microdissection sample carrier (102) with a membrane (108), which is configured to be cut by a laser microdissection device; wherein the membrane (108) has an opening, the diameter of which is smaller than the diameter of the electron microscope sample carrier (104); wherein the electron microscope sample carrier (104) is disposed on the opening of the membrane (108) in such a way that the mixture (400) is disposed on the side of the grid (110) facing the membrane (108) and the support layer (112) is disposed on the side of the grid (110) facing away from the membrane (108); and wherein at least part of the solvent has evaporated, so that the polymer has cured.