Failure Case Library

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

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

High Background with Nonspecific Bands

Western blot shows high background signal with multiple nonspecific bands, obscuring the target protein band and making interpretation difficult.

💡 6 causes ✓ 6 fixes
IP-Western Blot critical

No Target Protein or Insufficient Yield

Western blot shows no visible band for the target protein, or the band intensity is much weaker than expected, indicating little or no protein was eluted from the immunoprecipitation.

💡 7 causes ✓ 8 fixes
IP-Western Blot moderate

Extra Bands at 50 kDa and 25 kDa Masking Target

Western blot shows strong bands at approximately 50 kDa (heavy chain) and 25 kDa (light chain) that may mask or interfere with the target protein band of interest.

💡 3 causes ✓ 3 fixes
IP-Western Blot severe

Bead-Antibody Isotype Incompatibility

No or very weak target protein signal despite using adequate antibody concentration, suggesting inefficient antibody capture by the beads due to isotype incompatibility.

💡 5 causes ✓ 5 fixes
IP-Western Blot severe

Protein Complex Disruption in Co-IP

In co-immunoprecipitation experiments, expected interacting proteins are not detected on Western blot, suggesting protein-protein complexes were disrupted during sample handling.

💡 3 causes ✓ 3 fixes
IP-Western Blot moderate

Accidental Bead Loss During Aspiration

Inconsistent or absent target protein signal across replicate samples, with visible reduction in bead pellet volume, indicating beads were aspirated during wash or supernatant removal steps.

💡 3 causes ✓ 4 fixes