1-DNA profiling & PCR

• How are DNA profiles compared?

  • Compare total no. of bands
  • Compare the position of the bands
  • Compare the size/width of the bands
• Is DNA profiling reliable?

  Yes -

  • Everyone's DNA is unique

  No -

  • Multistep process - contamination
  • Identical twins have identical DNA profiles
  • Close relatives have similar DNA profiles
  • If only a few STRs are analysed, it is less reliable
• How to determines genetic relationship using DNA profiles?

  • Compare DNA profiles
  • To see how closely related they are
  • The more bands in common = more closely related
  • Can find a common ancestor