Boatloads of jobs are being posted to the CareersOnline website.. and when I say boatloads I mean literally hundreds of jobs, most of them part time on campus for students it seems. One of them that stuck out to me was a robotics technician lab job at the Hallam lab. Lulz I think I would be qualified. There weren’t any qualifications needed though other than being in Science because I guess they would teach you everything.
I helped someone else in the lab yesterday with their chromatin immunoprecipitation (ChIP) protocol, particularly the mononuclease digestion part.
There are many versions of ChIP, but basically you get some genomic DNA (e.g. from hematopoietic stem cells) and you digest the DNA using an enzyme called a mononuclease. Since mammalian DNA often presents itself as chromatin, the only DNA that will be digested is euchromatin (I am probably generalizing a bit here) which is the DNA that is unwound (“beads on a string”).
The mononuclease will digest the DNA, and the product will be a mixture of DNA fragments. It depends on the digestion time, but you’ll get a lot of fragments that are approximately 140 bp in size, and that’s the DNA that is wound around the histone proteins in each nucleosome. You might also get smaller fragments which is the linker DNA (but possibly other crap), and the chromatin stuff I guess that didn’t degrade.
The fragments that are very small, as well as large chromosomal fragments can easily be removed through DNA purification/selection methods. Here comes the immunoprecipitation part, where you add antibodies that are specific to certain histone tails (tails are linear polypeptides that are attached to the histone proteins) and you can then purify those from the other histones/nucleosomes and sequence that DNA. The purpose I suppose is to find what loci in the genome that are targeted by histone tail modification enzymes/processes. Histone tail modification is an important process because it affects the gene expression at that locus.
Of course, there are other applications to ChIP.
In addition to experiments stuff, I’m also trying to see if I can calibrate the robot to pipet accurately… accurately as defined as close to what I can pipet manually (a somewhat problematic definition). I’m currently trying to do it by weight of water.
Ah Syrup Trap, always lulzworthy: