Failure Case Library

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

All Techniques (8) 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)
Immunoprecipitation (High Background) severe

High Background from Insufficient Antibody Specificity

High background signal observed in immunoprecipitation experiments where multiple non-target protein bands appear in the eluate, indicating poor antibody specificity.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) severe

High Background from Antigen Degradation During IP

High background with smeared or degraded protein bands in IP eluate, often accompanied by loss of target protein signal. Multiple lower molecular weight bands appear below the expected target band.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) moderate

High Background from Incomplete Wash Steps

Persistent high background with many non-specific protein bands in IP eluate despite following standard protocol, indicating residual unbound proteins remain on beads.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) severe

Non-specific Protein Binding to Antibody

Multiple protein bands appear in IP eluate that are not related to the target antigen, indicating proteins binding non-specifically to the antibody Fc region or other antibody domains.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) moderate

Insufficient Bead Blocking Leading to Background

High background caused by non-specific proteins binding directly to the bead matrix surface rather than the antibody, appearing as multiple bands in negative controls with beads alone.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) moderate

Sample Overload Causing Non-specific Background

Excessive background signal with numerous protein bands in eluate due to using too many cells or too much lysate protein, overwhelming the antibody-bead binding capacity.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) moderate

Excessive Antibody Causing Non-specific Binding

High background observed when using too much antibody in the IP reaction, leading to increased non-specific protein interactions and higher background in the eluate.

💡 4 causes ✓ 4 fixes
Immunoprecipitation (High Background) moderate

Background from Insoluble Protein Carryover

High background in IP eluate with particulate matter visible, caused by insoluble proteins or cellular debris contaminating the soluble lysate supernatant.

💡 4 causes ✓ 4 fixes