Re: Testosterone Testing: More on False Positives

Bob Schwartz said:

wimpyVO2 said:

Validity of the Testosterone / Epitestosterone Ratio Technique
Simon Davis B.Sc., Ph.D.

Dumbass,

The c12/c13 ratio is the one that's going to be a [censored] to beat.

Bob Schwartz

Just about everything that 'wimpyVO2' said about the measurement of T/E
using GCMS could be said about the measurement of 13C:12C using
GC/C/IRMS.

Andy Coggan

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Quoted message said:

Bob Schwartz said:

wimpyVO2 said:

Validity of the Testosterone / Epitestosterone Ratio Technique
Simon Davis B.Sc., Ph.D.

Dumbass,

The c12/c13 ratio is the one that's going to be a [censored] to beat.

Bob Schwartz

Just about everything that 'wimpyVO2' said about the measurement of
T/E
using GCMS could be said about the measurement of 13C:12C using
GC/C/IRMS.

http://www.medscape.com/medline/abstract/11272321?prt=true

Endogenous natural human testosterone and its main metabolites excreted
into the urine in non-consumers of testosterone has been measured
at -21.3 to -24.4/1000 (delta 13C/1000 range) while testosterone from
consumers of various pharmaceuticals has been measured at -27.43 +/-
0.76/1000 (mean and SD). An individual with a naturally occurring delta
13C/1000 of -27.43 is 4 SDs away from the normal maximum. A 20% error
would of course make the test meaningless.

Phil H

Phil Holman said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Bob Schwartz said:

wimpyVO2 wrote:
> Validity of the Testosterone / Epitestosterone Ratio Technique
> Simon Davis B.Sc., Ph.D.

Dumbass,

The c12/c13 ratio is the one that's going to be a [censored] to beat.

Bob Schwartz

Just about everything that 'wimpyVO2' said about the measurement of
T/E
using GCMS could be said about the measurement of 13C:12C using
GC/C/IRMS.

http://www.medscape.com/medline/abstract/11272321?prt=true

Endogenous natural human testosterone and its main metabolites excreted
into the urine in non-consumers of testosterone has been measured
at -21.3 to -24.4/1000 (delta 13C/1000 range) while testosterone from
consumers of various pharmaceuticals has been measured at -27.43 +/-
0.76/1000 (mean and SD). An individual with a naturally occurring delta
13C/1000 of -27.43 is 4 SDs away from the normal maximum. A 20% error
would of course make the test meaningless.

Thank you for making my point for me.

Andy Coggan