Question: Can I freeze a cell pellet or whole blood?
Answer: Whole blood or cells/nuclei should not be frozen. Freezing cells without a cryoprotectant can compromise cellular membranes and negatively impact cell viability.
This document outlines four different protocols to thaw cryopreserved cell suspensions for use with 10x Genomics Single Cell assays. This document also provides guidelines in identifying the appropriate protocol(s) by providing a comparison of the protocol features, and indicating the key differences among the four thawing protocols.
Key points highlighted in this protocol:
- Use a cryoprotectant such as DMSO as indicated; this will preserve cell membrane integrity and cell viability.
- It is important to follow the slow-freeze recommendations; freezing cells too quickly may impact cell viability. Cells should be slowly frozen at -80C in an isopropanol bath or a cell freezing container(e.g., CoolCell FTS30).
- After slow freezing at -80C for 4 hours, cells should be moved to liquid nitrogen.
- Freeze cells at the appropriate cell density, cells are not happy at low densities, this can impact cell viability.
- Follow drop-wise thawing procedure; this step is important when trying to preserve sensitive cell types.
Isolated nuclei should not be frozen as pellets and should be used immediately for downstream 10x single-cell applications for best results.
Products: Single Cell Gene Expression, Single Cell Immune Profiling, Single Cell ATAC, Single Cell Multiome ATAC + GEX