Comet assay as DNA cuts more precise analysis :)

[Ivaylo]

Hello again I was talking about the comets that you get when treating DNA with factors that cut the DNA molecule, you start the electrophoresis and then on fluorescent microscope you see the fragments that have been cut.

 

http://library.wolfram.com/examples/cometassay/Images/index_gr_6.gif

 

Hello, I am characterising comet tails. I am not using a specific software for that, just Photoshop. I got problems cause when calculating the lenght of the comet tail, there are some fragments that are far away from ... how to say it... the main tail, that is intensively green. What should I do? Should I include them in the lenght of the whole comet? I am doing this for the first time and I will apreciate help of any kind.

[grifter]

ha ha I was wondering what was up with the green tails, so I spose this is out of my field lol, sorry about the confusion, i keep my astrophysics to myself in future lol

[Bluenoise]

I'm a bit confused at to what causes the clumping in the tail. Shouldn't you get an even smeer or gradient or at the most bands. This is a one dimensional seperation is it not?

 

What does this sort of assay involve. To me it looks like you have some hight molecular weight DNA "stuck" in a high density gel and you digest/degrade the DNA and perform electrophoresis simultaniously. Is this an assay for rate of degradation of the DNA?

[Ivaylo]

Yes, in most bands you get a density gradient, but in some you don't. You see the tail that ends somewhere, then you see black space and then you see green strains of Dna again, like little green spots, but they are seen. Yes, it is for measuring DNA degradation. Yes, you cut the DNA with an agent and then you perform the electrophoresis and see the DNA "moving away" from the cell.

 

 

http://cometassay.com/ here you can find more info. about it if you are interested