- 01 Introduction
- 02 Biology of DNA
- 03 Practical Issues Specific to DNA Evidence
- 04 Introduction to the Forensic DNA Laboratory
- 05 Assuring Quality in DNA Testing
- 06 Understanding a Forensic DNA Lab Report
- 07 Statistics and Population Genetics
- 08 Mitochondrial DNA & Y-STR Analysis
- 09 Forensic DNA Databases
- 10 Collection of DNA Evidence from Suspects and Arrestees
- 11 Pretrial DNA Evidence Issues
- 12 Victim Issues
- 13 Trial Presentation
- 14 Postconviction DNA Cases
- 15 Emerging Trends
Principles of Forensic DNA
for Officers of the Court
for Officers of the Court
Module 4 :: Intro To the Lab
Topic 2 :: Laboratory Processes Used in Forensic DNA Analysis
DNA Detection
After the DNA molecules have been separated by electrophoresis, the different DNA types, or alleles, must be detected. As a result of the amplification process, the different STR loci are prelabeled with different colored fluorescent dyes. Their respective alleles are detected by a laser that scans across the slab gel or capillary. On a slab gel, this is sometimes seen as colored bands that are captured in a digital image. An electropherogram, which is a recording of colored peaks, is produced on the CE instrument and some slab gel systems.
Click here to view an animation on how an electropherogram is generated.
