Are the PCR facts right?
I agree with the above to the extent that it sounds like McClure probably didn't understand the nature of the samples Wessely presented to her or CFS polics. She was just focussed on testing samples she was asked to test. No doubt she must also been influenced by him.
But she can no longer be so naive and she is responsible for public comments she makes. It seems to me she has been plainly inaccurate in a number of public comments, the latest of which appears in this article, as picked up earlier in this thread by Bob:
Additionally McClure's article says (bolding mine):
Compare the above to a direct quote from the WPI Science paper second para (bolding mine):
I understand nested PCR is double round PCR, not single round PCR.
I can't see how the McClure article can be interptreted as anything other than a misrepresentation of the facts in relation to the WPI study. Much of the criticism of the WPI in the article revolves around this PCR issue. I cannot fathom how McClure, with her intimate knowledge of WPI study, could have got this point wrong accidentally, unless there has been some 3rd party journalistic or editorial intervention here that has got things mixed up. Or maybe the other person wrote it. Not that that excuses anything.
If there is anyone here that understands how the above quotes can be reconciled then please enlighten us. Otherwise I think we should be writing to the journal asking for a public correction to be made and questioning how someone of McClure's knowledge and standing could be making such errors.
I'm sympathetic to McClure, and think she probably got suckered by Wessely into making unfounded comments as to her certainty that XMRV is not a factor in CFS in the UK.
I agree with the above to the extent that it sounds like McClure probably didn't understand the nature of the samples Wessely presented to her or CFS polics. She was just focussed on testing samples she was asked to test. No doubt she must also been influenced by him.
But she can no longer be so naive and she is responsible for public comments she makes. It seems to me she has been plainly inaccurate in a number of public comments, the latest of which appears in this article, as picked up earlier in this thread by Bob:
I'm not sure about the accuracy of the following quote:
One technical difference stands out from these studies. PCR was employed to amplify XMRV sequences in all four studies. Only the study from the Whittemore Peterson Institute [1] was able to detect XMRV sequences following single-round PCR, indicating that copies of the XMRV genome were not in short supply. All the others found it necessary to employ a nested PCR, a modification of the standard reaction designed to enhance sensitivity and specificity.
Additionally McClure's article says (bolding mine):
The new connection of XMRV with CFS reported from the Whittemore Peterson Institute (NV, USA), was published in Science last year [1], and claimed that, of 101 CFS patients recruited to investigate the virus etiology of the disease, 68 (67%) were XMRV positive by single-round PCR amplification of the proviral DNA from peripheral blood mononuclear cells.
Compare the above to a direct quote from the WPI Science paper second para (bolding mine):
we isolated nucleic acids from PBMCs and assayed the samples for XMRV gag sequences by nested polymerase chain reaction (PCR) (5, 6). Of the 101 CFS samples analyzed, 68 (67%) contained XMRV gag sequence.
I understand nested PCR is double round PCR, not single round PCR.
I can't see how the McClure article can be interptreted as anything other than a misrepresentation of the facts in relation to the WPI study. Much of the criticism of the WPI in the article revolves around this PCR issue. I cannot fathom how McClure, with her intimate knowledge of WPI study, could have got this point wrong accidentally, unless there has been some 3rd party journalistic or editorial intervention here that has got things mixed up. Or maybe the other person wrote it. Not that that excuses anything.
If there is anyone here that understands how the above quotes can be reconciled then please enlighten us. Otherwise I think we should be writing to the journal asking for a public correction to be made and questioning how someone of McClure's knowledge and standing could be making such errors.