Upon isolating a viable single-cell or nuclei suspension from your sample*, proceed to fixation (takes 30 min to 1 hour) to retain endogenous gene expression and sample stability. Upon successful completion of the EvercodeTM Cell Fixation, Nuclei Fixation, or Low Input Cell or Nuclei Fixation kit workflows you can store your fixed samples for up to 4-6 months (depending on the fixation kit) before proceeding to barcoding and library preparation. This makes it possible to store samples that were extracted and fixed on different days, then process them together in a single barcoding run.
*Note: Additional information on sample isolation:
If you plan to use cells that were previously cryopreserved, upon thawing your cryopreserved cells and prior to fixation, it is best practice to verify that the cells are still of high viability. You should also ensure that the cell suspensions are largely free of debris and aggregates before input into Evercode Cell Fixation or Low Input Cell Fixation.
If you plan to use tissue that has been flash frozen in liquid nitrogen and stored, due to the cellular damage that will occur as a result of the freezing process, this tissue should only be used for single-nucleus RNA-seq. Nuclei should be extracted from the tissue and fixed using an Evercode Nuclei Fixation or Low Input Nuclei Fixation kit prior to barcoding and library prep.