- Course Introduction
- 01: Evidence & DNA
- 02: Forensic Biology
- 03: DNA Extraction & Quantitation
- 04: DNA Amplification
- 05: Amplified DNA Product Separation
- 06: STR Data Analysis & Interpretation
- Data Troubleshooting
- Data Interpretation & Allele Calls
President's DNA Initiative
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Advancing Justice Through DNA Technology
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Advancing Justice Through DNA Technology
DNA Analyst Training
Positive Control(s)
Home > STR Data Analysis & Interpretation > Data Interpretation and Allele Calls > Step 1: Internal Size Standards and Allelic Ladders > Positive Control(s)
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Positive controls are included in most commercial DNA analysis kits used for quantitation or STR typing. Applied Biosystems and Promega STR kits both include 9947A control DNA for use as a positive amplification control. The control is usually amplified with each batch of samples and aids in determining the overall performance of the amplification and typing procedures. 9947A is a female cell line from a 31 year old Caucasian female. The cell type is B-lymphocyte from a blood sample. This cell line is used as a positive control in forensic DNA analysis.
Click here to read more about 9974A at Coriell Institute.
The positive control should show the expected alleles. If no peaks are seen, this may indicate a problem with the amplification or injection. In the event that the positive control does not yield the correct results, analysts should troubleshoot the problem and follow the procedures established by the laboratory.
Note: |
It is expected that injection issues would have been identified in the internal size standard evaluation step. |
