Methods for regioselective functionalizing a surface of an electron microscopy grid

A method for regioselective functionalizing a surface of an electron microscopy grid (EM grid) (10), preferably a surface of a cryo-electron microscopy (cryo-EM) grid, preferably a surface of an affinity EM grid or an affinity cryo-EM grid, comprising the steps of:

• i. providing a surface (20) of an electron microscopy grid (101) to be functionalized, preferably regioselective functionalized;
• ii. providing a plurality of wall systems (30A, 30B) on at least one part of the surface of an electron microscopy grid, thereby forming a plurality of temporary reaction chambers (40A, 40B) wherein the at least one part of the surface (21A, 21B) of an electron microscopy grid (10) forms a floor or a ceiling of the temporary reaction chambers;
• iii. providing a modification solution (50) or a different modification solution (50A, 50B) in each temporary reaction chambers (40A, 40B);
• iv. modifying the parts of the surface (21A, 21B) of an electron microscopy grid (10) in the temporary reaction chambers (40A, 40B) with the modification solution(s) (50, 50A, 50B) or components comprised in the modification solution(s) (50, 50A, 50B);
• V. removing the modification solution(s) (50, 50A, 50B) from the temporary reaction chambers (40A, 40B);
• and
• vi. removing the plurality of wall systems (30A, 30B) from the surface (20) of a microscopy grid (10), thereby providing a regioselective functionalized surface (22A, 22B) of an electron microscopy grid (10).

An apparatus for regioselective functionalizing a surface of an electron microscopy grid, comprising:

• i. a plurality of partially formed reaction chambers, each partially formed reaction chamber comprising at least a wall system;
• ii. for each partially formed reaction chamber, a fluid inlet and/or fluid outlet in fluidly connection to said partially formed reaction chamber;
• iii. an electron microscopy grid holder, to hold the electron microscopy grid and configured to expose the surface to be modified to the partially formed reaction chambers;
• and,
• iv. optionally, a press system or clamp system to press the electron microscopy grid and/or the object holder with the electron microscopy grid with the surface against the wall systems.