DNA Analysis

Question 1

What is DNA? How is it shaped?

Answer 1

Deoxyribonucleic acid, polymer shaped like a double helix.

Question 2

Mitochondrial vs YSTR DNA?

Answer 2

Mitochondrial - from mom

YSTR - from dad

Question 3

What are STRs? How do we calculate probability from them?

Answer 3

STRs = short tandem repeats. Short repetitive DNA sequences, 2-7 base pairs long.

1 STR site = roughly 1/10 probability of uniqueness. multiplies exponentially. (i.e. 3 STRs = (1/10 x 10/10 x 1/10) = (1/1000)

Question 4

What is CODIS and the Crime Scene Index?

Answer 4

CODIS = DNA software database

Crime Scene Index = >1 incident sharing the same DNA from an unknown offender

Question 5

Why do cold cases get revisited? What are some notable ones solved by DNA? (3)

Answer 5

New tech in DNA analyzing, can provide closure for victims and families.

Golden state killer Joseph DeAngelo.
OJ Simpson
Pauline Brazeau

Question 6

What are PCRs, probabilistic testing and the RCMP lab threshold?

Answer 6

PCR = polymerase chain reaction. DNA photocopying.

probabilistic testing = based on canadian population

threshold = 0.15 nanograms

Question 7

What is a DNA thermal cycler?

Answer 7

Automates rapid and precise temperature changes to copy DNA.