Let me share some insight regarding the EPO test and the case of Bernard Lagat:
1) The test is an immunoblot, also called a western blot. As a biochemist I do these on a regular basis. It is a 2 day procedure and there are several ways to mess it up. In the last few months my lab has performed hundreds of immunoblots.
2) Key to the success of a western blot is sample preparation. If the sample is not treated properly, proteases or other elements will degrade the protein of interest, in this case endogenous (natural) EPO.
3) The EPO test relies on a different recombinant EPO glycosylation pattern than endogenous EPO. (Glycosylation is the attachment of a small sugar group to a protein.) This means that the band pattern on an isoelectric focusing gel with be different because the glycosylation pattern is different. Also know that IEF gels are sometimes unreliable because of imperfections in the pH gradient.
4) Proteolytic or other decay of a protein, WILL CAUSE A SHIFT IN THE BAND PATTERN OF PROTEIN IN AN IEF GEL!
5) If Mr. Lagat's A sample was not properly treated prior to running the IEF gel, the band pattern of ENDOGENOUS EPO could easily shift to resemble that of recombinant EPO.
6) For the processing of the B sample, another scientist was brought in to make sure it was treated properly and there was no positive. The sample was likely treated properly hence there was no decay. Because there was no decay the band pattern wasn't artificially shifted.
7) Mr. Lagat claims he is innocent and the B sample confirmed it. The protocol for the current EPO test could (despite the claim of not one false positive--if they only tested standards, of course if won't give false positives, what about tests on humans using EPO and not using EPO and exposing urine to a wide variety of conditions before processing?) give false positives. For a good experiment, elaborate controls have to be set up or the results are unreliable.
8) As a biochemist who performs experiment like this and is conversant with the technology of the field, calling Mr. Lagat guilty is a quantum leap. All you fools who say, "he tested positive. He's guilty" really have no idea what you are talking about. Your ignorance is allowing you to blown by the wind of public opinion. Remain open minded.
9) I do not have any association with Mr. Lagat and have never met him. I hate to see people get ripped when it is not justifiable. Mr. Lagat is well educated and has a lot thing going for him besides track. He is one of the last athletes that would "need" to cheat.