Failure Case Library

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

All Techniques (7) 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)
LAMP (Loop-mediated Isothermal Amplification) severe

LAMP Reaction Orange Before Amplification Starts

The colorimetric LAMP reaction appears orange instead of pink/magenta prior to incubation at 65°C, indicating premature pH drop that compromises amplification.

💡 4 causes ✓ 5 fixes
LAMP (Loop-mediated Isothermal Amplification) critical

No-Template Control Turns Yellow (Contamination)

The no-template control (NTC) reaction turns yellow after incubation at 65°C, indicating contamination with amplifiable target nucleic acid or positive control template.

💡 4 causes ✓ 6 fixes
LAMP (Loop-mediated Isothermal Amplification) severe

Internal Control Fails Due to Sample pH Incompatibility

The internal control reaction fails to turn yellow after incubation at 65°C when spiked into sample, though it works in water, indicating sample matrix interference.

💡 4 causes ✓ 5 fixes
LAMP (Loop-mediated Isothermal Amplification) moderate

Internal Control Fails with Non-Human Sample Source

The internal control reaction fails to turn yellow when added to nucleic acid isolated from non-human sources (e.g., animal tissue, environmental samples), as the control targets human-specific sequences.

💡 3 causes ✓ 5 fixes
LAMP (Loop-mediated Isothermal Amplification) severe

Internal Control Fails Due to RNA Template Degradation

The internal control reaction fails to amplify when using RNA samples, while DNA-based controls work normally, indicating RNA-specific quality issues.

💡 5 causes ✓ 6 fixes
LAMP (Loop-mediated Isothermal Amplification) critical

Positive Control Remains Pink After Incubation

The positive control reaction fails to turn yellow following 30-minute incubation at 65°C, indicating no amplification occurred despite presence of target template.

💡 5 causes ✓ 5 fixes
LAMP (Loop-mediated Isothermal Amplification) moderate

Amplification Failure Due to Inadequate Reaction Mixing

Reactions show inconsistent color change or partial amplification with some replicates failing, caused by reagent stratification or incomplete mixing before incubation.

💡 4 causes ✓ 5 fixes