Flow Cytometry and Cell Sorting Sample Requirements 

These requirements apply to routine cell samples. Contact the laboratory for personalized guidance or recommendations for the preparation of specialized sample types 

1. Single-cell suspension
   Samples must be well-dispersed single-cell suspensions, with minimal aggregates and debris, in a buffer appropriate for the assay. No visible chunks should be seen in the solution. 
2. Biosafety approval
   Samples must be approved for handling in the facility. Disclose known or potential biological hazards before scheduling. Infectious, human-derived, or genetically modified samples require advance consultation and any applicable institutional approvals. 
3. Filtration
   Filter samples through a cell strainer with a pore size of 70 μm or smaller shortly before acquisition or sorting, unless an alternative has been approved by the laboratory. Whole-blood samples prepared by red blood cell lysis may be exempt if they are free of clumps. Confirm the appropriate filter size for unusually large or fragile cells. 
4. Appropriate cell concentration
   Count cells before the appointment and prepare samples at the concentration recommended by the laboratory. General starting ranges are 1–5 × 10⁶ cells/mL for analysis and 5–10 × 10⁶ cells/mL for sorting. The appropriate concentration depends on cell size, sample characteristics, and the assay. Cell concentration affects acquisition time and the sample flow rate needed, which can influence data quality and sorting performance. Bring additional sample buffer for dilution if needed. 
5. Viability dye for live-cell sorting
   Include a compatible viability dye for sorting live mammalian cells so that dead cells can be excluded. Confirm dye selection with the instrument configuration or with the laboratory before preparing samples. Exceptions must be discussed in advance.