PCR污染和携带污染

Symptom

Unexpected products appear in negative controls or multiple samples show identical non-specific bands, indicating contamination from previous amplifications or environmental sources.

1. 1 Aerosol contamination from pipetting high-concentration PCR products
2. 2 Exogenous DNA contamination from shared pipettors or work surfaces
3. 3 Contaminated reaction tubes containing biological inhibitors or previous DNA
4. 4 Poor laboratory practices allowing amplicon carryover

1. 1 Use aerosol-resistant (filter) pipette tips for all PCR setup and product handling
2. 2 Use positive displacement pipettes to prevent aerosol generation
3. 3 Set up dedicated work area and dedicated pipettor exclusively for PCR setup
4. 4 Autoclave empty reaction tubes prior to use to eliminate biological contaminants
5. 5 Wear gloves during all reaction setup and change frequently
6. 6 Prepare fresh reagent solutions and use new tubes when contamination suspected
7. 7 Physically separate pre-PCR and post-PCR work areas

Related Video (3)

Addgene ★ 78

Polymerase Chain Reaction (PCR) Protocol

"Covers complete PCR protocol with hands-on operational steps where contamination prevention practices during pipetting and sample handling are critical"

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PCR protocol fundamentals—hands-on operation guide

"Structured PCR hands-on operation guide that demonstrates proper technique and procedural safeguards to prevent aerosol contamination during amplification"

Bilibili (China-Accessible Mirrors) ★ 72

First-person PCR and gel electrophoresis demonstration

"First-person PCR workflow demonstration shows practical benchwork procedures where proper pipetting technique and contamination prevention are visible and learnable"