Question: After CMO-labeling and pooling, how long can cells or nuclei sit before loading onto the chip?
Answer: As with all of our Single Cell assays, our general recommendation is to load cells/nuclei onto the chip as soon as possible, within 30 minutes of preparing the final samples.
If CMO-labeled cell or nuclei samples are pooled together and left to sit for long periods of time, CMO tags from one sample may bind to cells/nuclei from another sample, increasing background noise in the Cell Multiplexing data and decrease the accuracy of the tag assignment algorithm. We have not specifically determined the maximum amount of time that pooled samples can sit before loading them onto the chip. Therefore, we suggest a general recommendation of loading samples onto the chip within 30 minutes after pooling.
Note for customers interested in performing flow cytometry:
We have performed in-house experiments where we pooled CMO-labeled cells together and performed flow cytometry on the pooled sample to enrich for viable cells. We observed excellent Cell Multiplexing data with these experiments. This suggests that the CMO tag was stable for the flow sorting experiment's duration and that tag exchange between samples in the pool was negligible.
Products: Single Cell Gene Expression, CellPlex