Home Failure Case Library Amplification Plots Dip Below Zero Due to Incorrect Baseline Settings
PCR (Sigma Guide) moderate

Amplification Plots Dip Below Zero Due to Incorrect Baseline Settings

Symptom
Amplification plots are clearly abnormal with sections dipping below zero dR; data cannot be used as presented; plots appear distorted
Common Causes
  1. 1 Inappropriate baseline settings applied by instrument software
  2. 2 Automatic baseline detection failed
  3. 3 Baseline cycles incorrectly defined
Solutions
  1. 1 Examine raw data plot to verify actual amplification profile is normal
  2. 2 Manually set appropriate baseline cycles based on raw data (typically the initial linear, baseline phase of the reaction, e.g., cycles 6 to 16)
  3. 3 Reanalyze data with corrected baseline settings
  4. 4 Consult instrument manual for proper baseline determination
Related Video (3)
Bio-Rad Laboratories ★ 90
CFX Manager™ Software Part 1: Setting Up Your Protocol
"Shows how to set up qPCR protocol in CFX Manager software, relevant to adjusting baseline settings that cause the issue."
Bilibili (China-Accessible Mirrors) ★ 80
qPCR Principles, Experimental Workflow and Results Analysis
"Covers qPCR data analysis and result interpretation, directly relevant to recognizing and understanding abnormal amplification plots."
Bilibili (China-Accessible Mirrors) ★ 70
Bio-Rad qPCR Instrument Operation Protocol
"Demonstrates Bio-Rad qPCR instrument operation and setup, helpful for understanding instrument software baseline options."
Source: sigmaaldrich.com ↗
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