How many cells are frozen per PromoCell cryovial, and how do I calculate viable cell numbers and optimal plating density?

Number of cells per cryovial
PromoCell guarantees ≥ 500,000 viable primary human cells after thawing. To ensure this, more than 500,000 cells are filled per cryovial before cryopreservation, since a fraction of cells does not survive the freeze-thaw process.
 
Viable cell number and Certificate of Analysis (CoA)
During quality control, PromoCell thaws representative vials per lot, determines viability, and calculates the number of viable cells recovered after thawing.
Both the viable cell number and the viability (%) are listed on the lot‑specific Certificate of Analysis (CoA).
Only the expected number of viable cells is reported; the total number of cells (viable + dead) is not specified.
Example:
If the CoA states 600,000 viable cells with 80% viability, the vial originally contained ~750,000 total cells, of which 600,000 were viable after thawing under PromoCell QC conditions.
No viability calculation by the user is required when the recommended thawing protocol is followed.
 
Calculating the optimal plating density
Use the number of viable cells stated on the CoA. Apply the recommended plating density for the specific cell type (e.g. 5,000-10,000 cells/cm²).
Example:
600,000 viable cells can be plated:
- into one T75 flask (~8,000 cells/cm²), or
- into one T75 + one T25 flask (~6,000 cells/cm²)