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

Cell Death from CO₂/pH Imbalance in Bicarbonate Buffer

Cells show progressive death over 24-48 hours with media color shift (phenol red turning yellow or purple). Cells exhibit membrane damage and eventual lysis despite sterile conditions.

💡 5 · ✓ 5

severe

Bacterial Contamination with Rapid Turbidity

Rapid-onset turbidity and color change of culture medium (when phenol red is present). Medium becomes cloudy and pH indicator changes color quickly.

💡 7 · ✓ 9

moderate

Contact Inhibition and Nutrient Depletion Cell Death

Cultures exceeding 80-100% confluence show central necrosis, detachment of cell sheets, and debris accumulation. Media becomes acidic (yellow) and depleted.

💡 4 · ✓ 5

moderate

Temperature-Induced Protein Precipitation in Culture Media

Turbidity or visible precipitates appear in cell culture media after temperature changes. High-molecular weight plasma proteins fall out of solution, creating visible cloudiness that may interfere with microscopy and imaging assays.

💡 4 · ✓ 4

moderate

Evaporation-Induced Salt Crystallization on Culture Surfaces

Crystal precipitates form readily on culture flask and plate surfaces. Media concentration increases due to water loss, causing salt components to exceed solubility limits and crystallize on plastic surfaces.

💡 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

moderate

Replicative Senescence After Excessive Passaging

Primary or finite cell lines show progressive slowing of growth, enlarged flattened morphology, failure to reach confluence, and increased spontaneous death after many passages.

💡 4 · ✓ 5