Forensic Genetics Week 4

What are the two methods that can promote DNA fluorescence?

1. Stain the DNA

2. Place a fluorescent label on the primer

How does fluorescent DNA staining work?

Uses intercalating dyes such as Ethidium bromide or SYBR Safe

Inserts between the strands of the DNA

Glows only when bound to the DNA and exposed to UV light

How do fluorescent primers work?

A fluorescent molecule is added to the 5’ end of one of the primers in a pair

What’s the term called that makes determining distinct colours difficult?

Spectral overlap

Up to how many colours can be detected at the same time when testing for STRs?

4-5

How can you go about changing the sizes of alleles and why is this necessary?

1. Moving the primers

2. Incorporating linkers

To avoid allelic overlap

How does incorporating linkers work?