Question: How long can the single cell or nucleus suspension be kept on ice?
Answer: Generally, we recommend loading cells/nuclei into the Master Mix and running the chip within 30 min of sample preparation. This is because cells/nuclei may clump or lyse if sitting on ice for long periods of time. The transcriptome may also be affected. The delay will affect different sample types differently.
Cells/nuclei should always be gently pipet mixed immediately prior to loading as they will settle to the bottom of the tube. Nuclei are particularly sticky and may require additional mixing to remove clumps.
In addition, if cells/nuclei have been sitting on ice for extended periods of time, we would recommend re-counting and checking the viability of the cells prior to loading.
Product: Single Cell 3', VDJ