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)
Cell Culture (Precipitates) moderate

Temperature-Induced Protein Precipitation in Culture Media

Turbidity or visible precipitates appear in cell culture media after temperature changes. High-molecular weight plasma proteins fall out of solution, creating visible cloudiness that may interfere with microscopy and imaging assays.

💡 4 causes ✓ 4 fixes
Cell Culture (Precipitates) moderate

Evaporation-Induced Salt Crystallization on Culture Surfaces

Crystal precipitates form readily on culture flask and plate surfaces. Media concentration increases due to water loss, causing salt components to exceed solubility limits and crystallize on plastic surfaces.

💡 4 causes ✓ 4 fixes
Cell Culture (Precipitates) severe

Trace Metal Precipitation in Serum-Free Formulations

Copper, iron, and zinc supplements precipitate out of serum-free media, creating a toxic environment for cells. Metal precipitates appear as dark particles and can compromise cell viability due to altered bioavailability and oxidative stress.

💡 4 causes ✓ 4 fixes
Cell Culture (Precipitates) moderate

Salt Precipitation from Concentrated Media Stocks

Concentrated media stocks (10x or higher) show salt precipitates particularly after refrigeration. Precipitates may redissolve upon warming but can lead to inaccurate final concentrations if not properly managed.

💡 4 causes ✓ 4 fixes
Cell Culture (Precipitates) severe

Calcium Salt Crystal Formation in Serum-Free Media

Insoluble calcium sulfate (CaSO4) crystals form in serum-free media preparations. Crystalline precipitates appear as visible artifacts under microscopy and may alter media composition by removing essential calcium.

💡 4 causes ✓ 4 fixes
Cell Culture (Precipitates) severe

Nutrient Loss via Chelation by Precipitates

Cell health deteriorates due to precipitate-mediated removal of essential nutrients. Precipitates chelate metal ions, vitamins, and other media components, effectively reducing their bioavailability and altering intended media composition.

💡 4 causes ✓ 4 fixes