Help! Please! Biology final question and I can't find anywhere in the book or online.

Question

is it a set list of steps? Is it a formula? I cannot find it anywhere and its on my biology final. What steps are followed to sequence the gene for sickle cell anemia? 

Thank you in advance!!

Answer 1

I've worked in DNA sequencing labs for over 10 years.  Here is a basic run down of how it works:

1) Perform polymerase chain reaction (pcr) on the section of DNA you want to sequence to provide many copies of the genes.

    For more info on pcr check this site: https://www.dnalc.org/view/15475-The-cycles-of-the-polymerase-chain-reaction-PCR-3D-animation.html

2) Once you have many copies of the gene, a cycle sequencing reaction is performed.  This reaction labels DNA strands with florescent tags corresponding to the DNA bases.

    More info on Cycle Sequencing (aka Sanger Sequencing) https://www.dnalc.org/view/15923-Cycle-sequencing.html

3) The Products of the sequencing reaction are separated on a gel based on size, and a laser is used to read the florescent tag on each fragment.

4) A computer program translates the data into a text sequence of the gene.

 

The links are really helpful in understanding the reactions - check them out.