As the studies progressed, it became clear that an assessment of pre-analytical variability was needed and so we examined the effects of leaving a sample at room temperature and at 4ºC for up to 4 days. We also examined the effects of repeat freeze thaw cycling on assay results. This information was used to inform WADA of the conditions require to take and transport blood samples to the laboratories.
These studies are complete and the results have been published in GH & IGF research (1) and Drugs Testing and Analysis (2).
Following the completion of these studies and published in peer-reviewed scientific journals, the laboratory procedures were established at the WADA-approved Anti-Doping Laboratory at King’s College, London and the test was fully and extensively validated by WADA. The ‘biomarker’ test for GH misuse was introduced for the London Olympic and Paralympic Games in 2012 where it caught two drug cheats who had been missed by the isoform test and who subsequently admitted taking GH. This confirmed the longer window of opportunity of the biomarker method.
Full details on publications resulting from this research can be found here.
(1) Holt RI, Erotokritou-Mulligan I, Ridley SA, McHugh CM, Bassett EE, Cowan DA, Bartlett C, Sonksen PH. A determination of the pre-analytical storage conditions for insulin like growth factor-I and type III procollagen peptide. Growth Horm IGF Res 2009 February;19(1):43-50.
(2) Guha N, Erotokritou-Mulligan I, Bartlett C, Cowan DA, Bassett EE, Stow M, Sonksen PH, Holt RI. The effects of a freeze-thaw cycle and pre-analytical storage temperature on the stability of insulin-like growth factor-I and pro-collagen type III N-terminal propeptide concentrations: Implications for the detection of growth hormone misuse in athletes. Drug Test Anal 2012 June;4(6):455-9.