American Society for Clinical Pathology (ASCP) Technologist in Cytogenetics certification (ASCP CG) Practice Test

Dimethyl sulfoxide (DMSO) is widely used for cryopreservation due to its ability to penetrate cell membranes and protect cells from the damaging effects of ice crystal formation during the freezing process. DMSO acts as a cryoprotectant, which reduces cellular damage and enhances the viability of cells upon thawing. Its low freezing point allows it to remain liquid at lower temperatures, making it suitable for the preservation of biological samples, including cells, tissues, and embryos.

Ethylene glycol, while sometimes used in specific applications, is not as commonly employed for biological cryopreservation due to potential toxicity to cells. Formaldehyde is primarily used as a fixative and is not suitable for cryopreservation as it can cause cross-linking of cellular proteins, leading to cell death. Glycerol is also used as a cryoprotectant, but its applications are less common than DMSO for most cell types, particularly in the field of cryopreservation for stem cells and gametes. Thus, DMSO is the preferred choice in various cryopreservation protocols.