Cell Culture Fundamentals: Revival, Passaging, Cryopreservation

critical

No/Few Viable Cells After Thawing Cryopreserved Stock

Upon thawing cryopreserved cell stocks, researchers observe minimal or no viable cells via trypan blue exclusion or hemocytometer counting. Cells appear non-adherent, crenated, or lysed.

💡 5 · ✓ 5

critical

Cell Death from Bacterial or Fungal Contamination

Media becomes rapidly turbid with visible particles or cloudiness. Cells show signs of toxicity, detachment, and death. Microscopy reveals motile bacteria or fungal filaments. Note: mycoplasma rarely causes acute cell death.

💡 4 · ✓ 6

severe

Calcium Salt Crystal Formation in Serum-Free Media

Insoluble calcium sulfate (CaSO4) crystals form in serum-free media preparations. Crystalline precipitates appear as visible artifacts under microscopy and may alter media composition by removing essential calcium.

💡 4 · ✓ 4

moderate

Salt Precipitation from Concentrated Media Stocks

Concentrated media stocks (10x or higher) show salt precipitates particularly after refrigeration. Precipitates may redissolve upon warming but can lead to inaccurate final concentrations if not properly managed.

💡 4 · ✓ 4