
How Does Performance Enhancing Drug Testing Really Work?
The majority of drugs that can be abused by athletes can be detected in samples of urine. Drug testing begins when an athlete submits an urine sample. The sample is then sent to a laboratory for analysis and the results are reported back to regulators. For some substances, blood samples or used instead of urine.
Gas Chromatography & Mass Spectrometry
Gas chromatography and mass spectrometry are the most common methods of chemical analysis. In class, we learned that chromatography is one of the processes used by Genentech to purify monoclonal antibodies.
For this application, chromatography is used to vaporize the sample in the presence of a gaseous solvent and placed through a long path of a machine. Each substance dissolves differently in the gas and stays in the gas phase for a unique amount of time, called the retention time. Typically the substance comes out of the gas and is absorbed on to a solid or liquid, which is then analyzed by a detector. After the sample is analyzed, the retention results are plotted to create a chromatogram. Standard samples of drugs are run, so that specific drugs can be identified and quantified in the chromatograms of the urine/blood samples. Doing this allows scientists to recognize any irregularities in the subject's urine.
Mass spectrometry is an analytical process for determining elemental composition of a sample. In this case, mass spectrometry is used to blow samples apart with an electron beam and the fragments are accelerated down a long magnetic tube to a detector. Each substance has a unique "fingerprint" in the mass spectrometer. Again, standard samples are run for identification and quantification of drugs in the urine/blood samples.
Some substances (such as HCG, LH, ACTH) can be measured in urine samples using an immuno-assay. In this test, the sample is mixed with a solution containing an antibody specific to the tested substance. From E25, an antibody is a protein that binds only a specific substance and is how the body recognizes foreign substances. Scientists use fluorescence activated cell sorting and fluorescent dye molecules to tag the antibody. Then, the amount of fluorescent light or radioactivity is measured and is related to the concentration of the tested substance in the sample.
Tests Under Development
Currently, there are no reliable tests for HGH, IGF-1 and EPO. However, a test for EPO is being developed. The EPO test examines the size of red blood cells. It has been noticed that synthetic EPO produces red blood cells that are smaller and bind more iron then natural EPO. So, the size and iron content of red blood cells from a blood sample are analyzed to determine whether an athlete has used EPO.
As new performance-enhancing drugs are developed, new tests are developed to detect these drugs, and the struggle to keep sports clean continues indefinitely.
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