Complete Absence of PCR Product (PCR / RT-PCR Amplification Problems)

Question

Accepted Answer

No bands visible on agarose gel after PCR amplification, indicating complete reaction failure. Common causes: 1) Thermal cycler malfunction or incorrect temperature calibration 2) Insufficient template (too little) or excessive template (too much) concentration 3) Poor DNA quality or presence of PCR inhibitors in template 4) Primer concentration too low or unbalanced between forward and reverse primers 5) Nuclease contamination degrading template or primers 6) For RNA templates: EDTA in RNA solution chelating required Mg2+ ions Solutions: 1) Test with positive control using validated template and primers; repair/calibrate thermal cycler 2) Titrate template concentration systematically for your specific system 3) Use freshly prepared DNA or isolate template by alternative purification method 4) Ensure primer concentration within recommended range and equal for both primers 5) Prepare new template following strict nuclease-free protocols, especially for RNA 6) For RNA: Add additional Mg2+ to compensate for EDTA chelation per product instructions