Page 10 - It's in the DNA_Neat

They take the ataxia gene DNA copies that they made in the tube and put it into a
tiny well in the gel. Now, they put the gel in a tank of salt solution and put electrodes
at both ends. The DNA is negatively charged, so it likes to move towards the pos-

itive electrode.

Dadaji’s DNA had two copies of the ataxia gene, one the normal length and the
other was really looooong! In the gel, all the normal copies being smaller would run
towards the positive electrode quickly. But the looooong pieces would get trapped
in the mesh of the gel more often and they would lag behind. After sometime we
took the gel and shine a UV light on it.

Lo and behold, we could see two bands for some samples while other had only one

normal sized band. So that’s what they would so to Papa’s DNA to find out if he got
two normal ataxia genes or one abnormally long one and a normal one.

Let me share the gel picture we got from the lab for our family. Can you figure out
how the scientist would draw the pedigree map now?

Learn more at
www.yourgenome.org/facts/
what-is-gel-electrophoresis