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)
Flow Cytometry (Compensation) severe

Antibody fails to bind compensation beads

Compensation beads show no or minimal fluorescent signal when stained with antibody, preventing creation of valid single-stain controls for compensation matrix calculation.

💡 4 causes ✓ 4 fixes
Flow Cytometry (Compensation) severe

Compensation beads saturate detectors causing overflow

Compensation bead populations appear off-scale or saturate detectors, producing signals outside the linear detection range and preventing accurate compensation matrix calculation.

💡 4 causes ✓ 4 fixes
Flow Cytometry (Compensation) severe

Tandem dye degradation on compensation beads

Tandem fluorophore compensation beads show spectral shift or altered emission profile over time, causing incorrect spillover calculation and poor compensation in acceptor channels.

💡 4 causes ✓ 5 fixes
Flow Cytometry (Compensation) critical

Incorrect compensation beads for fixable viability dyes

Fixable viability dyes (LIVE/DEAD, Zombie dyes) show no signal on standard antibody-capture beads or produce inconsistent compensation when using stained cells, causing spillover errors into viability channels.

💡 4 causes ✓ 5 fixes
Flow Cytometry (Compensation) severe

Compensation bead staining conditions mismatch experimental protocol

Compensation matrix fails to correctly remove spillover from biological samples despite proper bead staining, resulting in false-positive populations or residual spillover in multicolor panels.

💡 5 causes ✓ 5 fixes
Flow Cytometry (Compensation) severe

Poor spectral reference controls for unmixing algorithms

Spectral unmixing (Cytek Aurora, Sony ID7000) produces residual spillover or negative populations despite using compensation beads, indicating unreliable full-spectrum reference signatures.

💡 5 causes ✓ 5 fixes
Flow Cytometry (Compensation) moderate

Dim or inconsistent compensation bead staining

Compensation beads display weak fluorescence or show highly variable signal intensity between replicates, producing unreliable compensation controls and inconsistent spillover correction.

💡 5 causes ✓ 5 fixes