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PCR / RT-PCR Amplification Problems severe

No Product Due to Suboptimal Cycling Parameters

Symptom
No amplification product visible despite proper template and reagents, suggesting thermal cycling conditions are inappropriate.
Common Causes
  1. 1 Primer annealing temperature too high, preventing primer binding
  2. 2 Denaturing temperature suboptimal, especially for GC-rich templates
  3. 3 Extension time too short for target amplicon length
  4. 4 Reagents not properly thawed and mixed before use
Solutions
  1. 1 Decrease annealing temperature in 2°C increments
  2. 2 Increase temperature or duration of initial denaturation step for GC-rich templates
  3. 3 Increase extension times, especially important for long PCR products
  4. 4 Thaw and thoroughly mix all reagents before setting up reactions
Related Video (3)
Addgene ★ 85
Polymerase Chain Reaction (PCR) Protocol
"Walkthrough of the PCR process itself, providing the context in which annealing temperature and cycling parameters must be correctly set."
YouTube (Curated Tutorials) ★ 80
Primer Design: Important Considerations and Tips for Good Primer Design
"Covers primer design considerations like Tm, which directly relates to choosing an appropriate annealing temperature and avoid the stated failure cause."
Bilibili (China-Accessible Mirrors) ★ 70
First-person PCR and gel electrophoresis demonstration
"Hands-on PCR and gel electrophoresis demonstration showing how no-product outcomes are visualized and the benchwork where cycling conditions apply."
Source: sigmaaldrich.com ↗
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