I know people have been working for a while to extract DNA from urine, but it's tough. There's a very low quantity and the conditions aren't ideal. Often it degraded before you can purify and amplify it.
Anyone know much more about this? Sounds like the IAAF got good samples. But last I knew it wasn't very efficient. I'd be interested to see these tests.
degrades*
I highly doubt the IAAF would have requested suspension of athletes at this top elite level if they were not highly confident that their DNA Convergance test was nearly foolproof.
Like with the stealth molecule test we read about last week, I believe the IAAF and WADA are not announcing new tests that they have extensively tested and approved for use. They just start using a new approved test and guess what, they immediately catch some big fish.
Drug Buster wrote:
I highly doubt the IAAF would have requested suspension of athletes at this top elite level if they were not highly confident that their DNA Convergance test was nearly foolproof.
Like with the stealth molecule test we read about last week, I believe the IAAF and WADA are not announcing new tests that they have extensively tested and approved for use. They just start using a new approved test and guess what, they immediately catch some big fish.
That was my first thought too.
Especially with the EPO cheats being caught. It sounds like they have a new EPO test that they're not letting people in on and they came out with "uhhhh oh there's a secret molecule". I don't know about the secret molecule theory. But I guess it's reasonable.
I just asked because I hadn't heard of a good and effective method to obtain DNA from Urine for convergence testing. Maybe you're right.
Could DNA convergence mean they all had the same granddad or greatgrandmother?
Effective procedures exist for issolating DNA from blood.
Yes you get a low amount of DNA but you do not need much DNA to run genotype test. Methods are so good for amplification and PCR today nanogram quanities are all thats needed. Degradation does occur but can be minimized by storage conditions and neutralization prior to extraction. Analysis is highly accurate and equivalent to any other DNA examined. These procedures have been well tested, sustantiated, and optimized for reliability.
If the sample was blood, tons of DNA will be recovered.
If the sample was urine, a small quantity of epithelial cells will have sloughed into the urine and contain a small amount of DNA. Urine itself is acellular and sterile.
DNA amplification (PCR) procedures can utilize sub-nanogram amounts of DNA.
I would assume that the sample is frozen or stored in preservatives such that DNA degradation is not severe. Even so, the test uses small amplification of small fragments of DNA such that ample template exists even in degraded samples.
The genetic assay itself is extremely accurate, since the goal is simply to exclude the athlete as a potential donor of the DNA sample.
Convergence?!!!!
Molecular Biologist wrote:
If the sample was blood, tons of DNA will be recovered.
If the sample was urine, a small quantity of epithelial cells will have sloughed into the urine and contain a small amount of DNA. Urine itself is acellular and sterile.
DNA amplification (PCR) procedures can utilize sub-nanogram amounts of DNA.
I would assume that the sample is frozen or stored in preservatives such that DNA degradation is not severe. Even so, the test uses small amplification of small fragments of DNA such that ample template exists even in degraded samples.
The genetic assay itself is extremely accurate, since the goal is simply to exclude the athlete as a potential donor of the DNA sample.
Yea yea, I know all about PCR, I was just wondering the state of the cells being released in the urine, and the amount of recoverable DNA that you can obtain from this. I had thought it was a pretty low amount, but I guess not. Obviously if they had blood samples this wouldn't be a problem.
Also what is the chance of contamination, say from sex or something that cells from someone else sorta rub off on that area? I'd have to assumed that IAAF seems quite content with the test, but I just wonder.
PCR has worked on single cells, though admittedly I have found that difficult. I don't have first hand experience with PCR from urine, but assume thousands of epithelial cells from the urogenital tract would be recovered. Perhaps an MD might comment on that.
I shouldn't speculate, but I would think it unlikely that exogenous cells would make it into the urethra, and if so would be vastly outnumbered by endogenous cells. Still, it seems it would be prudent to clean one's self before submitting a sample. A mixed DNA fingerprint would suggest tampering. For example, one could add some of your own DNA into someone else's urine. The mixture would be apparent. So an innocently providing a mixed sample (i.e., having sex, then submitting a urine sample) could look pretty bad.
Of course contamination in the lab could lead to preferentially amplifying the contaminant DNA, particularly if the level of DNA in the sample is low. There are kits for extracting DNA from urine (see below) note the precautions they suggest to avoid contamination. They also recommend the use of protease inhibitors something we know IAAF doesn't do (Lagat case).
http://www.norgenbiotek.com/tech%20downloads/Product%20Protocols/PI18100.pdf
You're a grad student, and you can't spell "convergence?" That's pretty rough.
wow..... wrote:
You're a grad student, and you can't spell "convergence?" That's pretty rough.
I can't spell a lot of words. English is by far my worst subject, pretty much cause I don't care about it, at all. I think it's silly. I could probably learn proper sentence structure and tenses and spelling...I just don't care though. I've never seen a life saved because someone spelled convergence correctly. Science, electrophysiology, modeling... that is interesting stuff. Spelling words correctly? Don't care. Unless I'm butchering it to the point where you can't understand me, then I can see legitimate gripes about spelling errors.
Grad Student wrote:
wow..... wrote:You're a grad student, and you can't spell "convergence?" That's pretty rough.
I can't spell a lot of words. English is by far my worst subject, pretty much cause I don't care about it, at all. I think it's silly. I could probably learn proper sentence structure and tenses and spelling...I just don't care though. I've never seen a life saved because someone spelled convergence correctly. Science, electrophysiology, modeling... that is interesting stuff. Spelling words correctly? Don't care. Unless I'm butchering it to the point where you can't understand me, then I can see legitimate gripes about spelling errors.
It's rather silly to not care about the things at which you are poor. English majors might not save lives, but neither do Doctors. Doctors only prolong lives, while English, if someone is really good at it can make this existence a little funny or more enjoyable. Each has it's purpose and function, thus one is no better that the other, although you'd never tell that by the pompous attitude.