Gel Electrophoresis Guided Notes
Name___________________________
Detecting blood factors
What are blood factors, and how can we determine which factors people have?
Blood factors are _________________________________ found in blood that
 Are _______________________________
 _____________________________ between individuals
There are a variety of ways to detect different blood factors, including:
 __________________________________________________________ (ABO, Rh)
 _________________________________________________________ (enzymes)
Gel electrophoresis
Gel electrophoresis is a method of separating
molecules (usually proteins or DNA) by
___________________________
__________________________________.
o
Scientists will also run known
samples for comparison
o
This method is sufficient to separate
DNA – additional methods often
used for proteins
o
Samples are loaded into wells of a gel
o
An electric current is put across the gel
with the positive electrode opposite the
wells
o
Negatively charged particles (such as
DNA and some proteins) diffuse across
the gel towards the positive electrode
o
Dyes are added to the samples so that
you can see them as they move down
the gel
o
Molecules move down gel at different
rates due to size and charge
How?
_____________________________
_______________________________
Gel electrophoresis question 1
A scientist added four substances to this gel.
1. Small, highly positively charged
chemicals
2. Small, slightly positively charged
chemicals
3. Large, highly positively charged
chemicals
4. Large, slightly positively charged
chemicals
Which is which?
Gel electrophoresis Question 2
The story …
Police searched the home a person
suspected of murder and found a shirt with
blood stains.
The blood type of the suspect, the victim,
and the blood on the shirt was all O+, so the
forensic serologist examined additional
blood factors, including PGM.
 What PGM factor does each sample
have?
 Who is the most likely source for the
blood stain?
 What is the value of a reference
sample?