DNA experts around? (and no, please, no political experts! ;) )

[Calcoran]

Originally posted by Fesarius
It used to take a very long time to do the test because the markers had to be compared manually (techs looked at photos of each sample, and established a certain number of similarity markers). Modern techniques automate the process, which produces more reliable results in a far shorter time.

Ah, maybe that's why I was confused .

Well, thanks everyone, at least I'll have learnt something today .

[Questor]

I´ve heard that an DNA - Test takes 4 hours to get an first (or exact) result.

Maybe my information may be wrong, but when you got the right equipment along it sounds possible.

- Questor

[Capt.Hunter]

Even a high-speed PCR machine (to amplify the DNA) will take at least a coupla hours due to the ramp time between temperatures.

PCR 101: The DNA is mixed with short DNA sequences that an enzyme can use as primers to make copies of the DNA. The DNA is heated to 95oC to split apart the two nucleotide strands, then cooled to 50-60oC to let the primers bind to it. The sample is then heated to 72oC so the enzyme can make the copies. This process needs to be repeated 20-30 times (and takes about 3-5 minutes each time) to get exponential amplification of the DNA and, factoring in ramp time, a run can take 3-4 hours. More costly machines have shorter ramp times and so can do it faster, but still an hour or so is the minimum.

Then there's the time it takes to analyze the samples via gel electrophoresis and compare them using software - at least a day, working around the clock. Bear in mind also that I'm used to working on plant DNA, where it doesn't matter so much about contamination with my own DNA - work on human samples will take longer due to all the precautions against getting the lab tech's DNA contaminating the sample...

[Calcoran]

Oh, so some say a few hours, some say a whole day at the very least ... C.Hunter seems to be the real expert here, so I guess we can believe him (unless he's been drinking too much to celebrate his birthday (<I>happy birthday C.Hunter btw!</I>)) ... so either we have the media goofing up a story (as usual) ... or something darker going on. Oh well, maybe someday we'll know the truth .

[Capt.Hunter]

"Drinking too much to celebrate my birthday"... HAHAHAHAHA!!!! They haven't made enough booze for that to happen!!!

[Balok]

He was in custody for around 30 hours before the capture was revealed. I think it's possible to do a DNA test in about a day, using the best equipment. Guess what they have at the FBI crime lab, to cite only one place?