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)
Western Blot (Detection Problems) severe

No Bands with Recombinant or Overexpressed Protein

No bands appear when testing recombinant protein or overexpression lysate, despite expected high protein levels, indicating structural or epitope accessibility issues.

💡 3 causes ✓ 3 fixes
Western Blot (Detection Problems) moderate

Membrane Type Contributing to High Background

Persistent high background signal related to membrane choice, particularly when using PVDF membranes which generally produce more background than nitrocellulose.

💡 3 causes ✓ 3 fixes
Western Blot (Detection Problems) severe

Temperature-Dependent Sample Degradation

Protein degradation, dephosphorylation, or denaturation occurs when samples are kept above 4°C throughout the protocol, resulting in high background or loss of target bands.

💡 3 causes ✓ 3 fixes
Western Blot (Detection Problems) severe

Sample Lanes Faint While Ladder Normal

Only sample lanes show faint or absent bands while molecular weight ladder is clearly visible, suggesting issues specific to target protein detection rather than general transfer problems.

💡 5 causes ✓ 5 fixes
Western Blot (Detection Problems) moderate

High Background Signal Across Membrane

Excessive background signal across the membrane obscures specific bands, caused by non-specific antibody binding, inadequate blocking, or improper handling.

💡 6 causes ✓ 6 fixes
Western Blot (Detection Problems) critical

All Bands Including Ladder Faint or Absent

All bands on the blot, including the molecular weight ladder, are difficult to see or completely absent, indicating a systemic technical problem rather than target-specific detection failure.

💡 5 causes ✓ 5 fixes
Western Blot (Detection Problems) moderate

Weak Lysis Method Causing Nonspecific Bands

Insufficient lysis strength results in incomplete protein extraction, leading to weak target signal and increased nonspecific bands from partially solubilized proteins.

💡 3 causes ✓ 3 fixes