Abnormal Amplification Plots Due to Excessive Template Concentration

Symptom

Very low Cq values for concentrated samples; amplification plots are not regularly spaced and appear abnormal; background fluorescence is significantly higher; minimal fluorescence yield through the reaction

1. 1 Too much template included in the PCR reaction
2. 2 Template concentration is too high for the reaction to be efficient
3. 3 Instrument cannot effectively process baseline data at very high template concentrations

1. 1 Dilute template to appropriate working concentration
2. 2 Use template quantity within recommended range for the protocol
3. 3 Prepare fresh dilution series with appropriate concentrations
4. 4 Verify template quantification accuracy

Related Video (3)

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Polymerase Chain Reaction (PCR) Protocol

"Walkthrough of the standard PCR protocol from Addgene, the same source as the failure case, showing correct setup including template addition."

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How to Optimize qPCR using SYBR Green Assays - Ask TaqMan #38

"Covers qPCR optimization for SYBR Green assays, directly relevant to interpreting abnormal amplification plots and background fluorescence from excess template."

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PCR protocol fundamentals—hands-on operation guide

"Structured step-by-step PCR hands-on protocol with operational guidance, useful for seeing correct reagent/template handling to avoid overloading."