The core has a Nexcelom Cellometer Auto 200 that can provide cell density and % viability.
10X has developed a protocol for methanol fixation that allows later processing of the sample.
The Satija lab at NY Genome Center has developed cells hashing that uses bar coded antibodies to pool samples.
Original Papers:
https://genomebiology.biomedcentral.com/articles/10.1186/s13059-018-1603-1
https://cite-seq.com/cell-hashing/
Commercial protocol/products:
https://www.biolegend.com/NewsLegend/091818hashtags/index.htm