Cryoembedded cell concentrates, methods for making, and methods for using

A method of preparing a cryoembedded cell concentrate, the method comprising:

• washing cultured cells two to five times with a one or more wash solutions, and the final wash solution is a serum-free media, saline, or PBS and is different from the previous wash solution(s);
• centrifuging the cultured cells at a speed of about 335 g;
• extracting substantially all of the extracellular fluid by one or more pipetting steps, to provide a cell concentrate;
• flash freezing the cell concentrate;
• cryoembedding the frozen cell concentrate in an embedding medium, to provide the cryoembedded cell concentrate such that the ultrastructure and target specificity of the cells in the cryoembedded cell concentrate are substantially maintained, as compared to the cultured cells;
• curing the cryoembedded cell concentrate, and
• cutting the cryoembedded cell concentrate into sections, to provide sections that are not suitable for use with an electron microscope.