Failure Case Library

Real lab failures, root causes, and fixes — curated and bilingually annotated by our team.

All Techniques (7) Nucleic Acid Quantification (9) Lipid Transfection (8) End-point PCR Primers (9) Cell Culture (Contamination) (7) PCR (Sigma Guide) (12) Flow Cytometry (Controls) (8) PCR / qPCR Plastics (9) PCR (Invitrogen Guide) (8) Cell Culture (Precipitates) (6) Cell Culture (Cell Death) (8) ELISA (Sigma Guide) (6) PCR / RT-PCR Amplification Problems (5) Flow Cytometry (Paraformaldehyde Fixation) (14) Flow Cytometry (Sample Considerations) (14) ELISA (R&D Guide) (10) Western Blot Immunodetection (19) Flow Cytometry (CST Guide) (8) Immunohistochemistry (CST Guide) (14) Immunoprecipitation (CST Guide) (14) ChIP (CST Guide) (8) ELISA Development (9) Western Blot (Sigma Protocol) (8) IP-Western Blot (6) Western Blot (CST Guide) (8) Flow Cytometry (Fixation Buffers) (7) Flow Cytometry (Isotype Controls) (7) Flow Cytometry (Fixation & Permeabilization) (9) Flow Cytometry (Fc Blocking) (7) Flow Cytometry (Compensation) (7) Flow Cytometry (Autofluorescence) (7) Flow Cytometry (Troubleshooting) (8) Tissue Imaging (Autofluorescence) (9) ELISPOT (8) Immunoprecipitation (Protein Obstruction) (1) Immunoprecipitation (No Protein Detected) (5) Immunoprecipitation (High Background) (8) Immunoprecipitation (High Antibody Elution) (1) Immunohistochemistry (No Staining) (9) Immunohistochemistry (High Background) (9) ChIP (PCR Amplification Problems) (4) ChIP (Low Signal) (8) ChIP (Low Resolution with High Background) (6) ChIP (High Background) (1) Western Blot (Blue Background) (1) Western Blot (Unusual Gel Band Appearance) (3) Western Blot (Unexpected Multiple Bands) (7) Western Blot (Misshapen / Uneven Bands) (5) Western Blot (Bands at Wrong MW) (5) Western Blot (Detection Problems) (7) Western Blot (Weak / No Signal) (6) ELISA (Standard Curve Fit Problems) (6) ELISA (Inconsistent Results / High CV) (6) ELISA (High Background) (8) ELISA (Signal Problems) (11) ELISA (Competitive) (18) Cell-free DNA Extraction (8) Bacterial rRNA Depletion (4) RNA Depletion for RNA-seq (7) LAMP (Loop-mediated Isothermal Amplification) (7) HMW DNA Extraction (Monarch) (7) NGS Library Preparation (NEBNext Ultra II) (7) RNA Cleanup (4) DNA Cleanup & Plasmid Purification (7) PCR (Polymerase Chain Reaction) (26) Restriction Enzyme Digest (13) Western Blot (9) Immunohistochemistry (IHC) (6) Colony Formation Assay (10) Transwell Migration / Invasion Assay (5) qPCR (RT-qPCR) (5) Transfection (8) Plasmid Construction (1) Sanger Sequencing (2) Plasmid Mini-prep (1) Plasmid Construction (Double Digest) (1) Protein Extraction (4) Transfection (Co-transfection) (1) Transfection (siRNA Knockdown) (1) CCK-8 Cell Viability Assay (5) Wound Healing Assay (5)
Cell Culture (Contamination) 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 causes ✓ 8 fixes
Cell Culture (Contamination) 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 causes ✓ 9 fixes
Cell Culture (Contamination) 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 causes ✓ 6 fixes
Cell Culture (Contamination) 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 causes ✓ 7 fixes
Cell Culture (Contamination) 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 causes ✓ 8 fixes
Cell Culture (Contamination) 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 causes ✓ 7 fixes
Cell Culture (Contamination) 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 causes ✓ 9 fixes