Complete Cell Culture Protocol: Revival, Passaging, Cryopreservation

critical

Mycoplasma Contamination - Silent Growth Inhibitor

Slowed cell growth, altered cellular metabolism, chromosomal aberrations, and interference with cell attachment. No visible turbidity in medium. Difficult to detect by light microscopy due to small size (0.15-0.3 µm).

💡 6 · ✓ 7

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

critical

Viral Contamination - Difficult to Detect

Unexplained cell detachment, poor cell health, or cell death. Non-cytopathic viruses may show no obvious signs. Cannot be detected by conventional light microscopy. May not present significant effects if virus is host/tissue-restricted.

💡 6 · ✓ 7

critical

Cell Death Due to Incubator Temperature Instability

Previously healthy cultures show sudden widespread cell death with membrane blebbing, crenation, and cellular debris. Cell death occurs within hours of incubation.

💡 4 · ✓ 5

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

Cell Death from Poor Quality or Toxic Reagents

Sudden cell death occurs immediately after introducing new lot of media, serum, trypsin, or buffer. Previously healthy cultures show rapid necrosis or apoptosis within 12-24 hours.

💡 5 · ✓ 6

severe

Trace Metal Precipitation in Serum-Free Formulations

Copper, iron, and zinc supplements precipitate out of serum-free media, creating a toxic environment for cells. Metal precipitates appear as dark particles and can compromise cell viability due to altered bioavailability and oxidative stress.

💡 4 · ✓ 4

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

severe

Fungal and Yeast Contamination

Visible turbidity and color change of medium. Fungal structures visible under standard light microscopy. Rapid onset similar to bacterial contamination. May include visible mold growth.

💡 6 · ✓ 8

severe

Contamination from Aerosol Generation

Multiple cultures becoming contaminated simultaneously or in sequence. Contamination spreading despite apparently good technique. Cross-contamination between neighboring cultures.

💡 7 · ✓ 9

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

severe

Nutrient Loss via Chelation by Precipitates

Cell health deteriorates due to precipitate-mediated removal of essential nutrients. Precipitates chelate metal ions, vitamins, and other media components, effectively reducing their bioavailability and altering intended media composition.

💡 4 · ✓ 4

moderate

Incubator-Associated Mold Contamination

Recurring fungal contamination in cultures after incubation. Multiple cultures affected over time. Visible mold growth may appear on incubator surfaces. Persistent contamination despite replacing affected cultures.

💡 6 · ✓ 8

moderate

Photooxidative Cell Death from Fluorescent Light Exposure

Cells cultured near fluorescent lights or windows show increased death rates, membrane blebbing, and oxidative stress markers. HEPES-buffered media particularly affected.

💡 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

Chemical Contamination from Residues

Poor cell growth, cell death, or altered cell behavior without visible microbial contamination. May include effects from free radicals, metal ions, disinfectant/detergent residues, or endotoxins persisting after bacterial contamination is cleared.

💡 6 · ✓ 6