Is a LC/MS test preferable for testosterone?

Discussion in 'Steroid Forum' started by Goingstronger, Aug 12, 2018.

  1. Goingstronger

    Goingstronger Member

    It’s pretty unequivocal that Ultrasensitive LC/MS test is a MUST to test estrogens in men.

    I saw that Quest is offering a LC/MS testosterone test, is there any benefit for this over the regular test?
     
  2. master.on

    master.on Member

    The big advantage is that it's guaranteed not to cross react to other steroids.

    Most T tests are immunoassay, which can crossreact a little bit. But when other steroids are used at high dosages (and don't we all?), potential for cross reaction increases.

    LC-MS-MS is Liquid Chromatography as good as separating chemical compounds as HPLC does
    and MS-MS is even more accurate at identifying steroids than GC-MS

    Bottomline: if it's available in your area, and not much more expensive go for it.
    It'd be nice if you can get immunoassay and LC-MS-MS taken together to compare results.



    Question 4. What is the advantage of using LC/MS/MS for testosterone measurements in women and children?
    Using LC/MS/MS technology, we are able to achieve higher sensitivity and specificity in complex matrices such as human serum and plasma. While immunoassay has been the dominant testing platform, LC/MS/MS technology is now widely accepted as the gold standard for small molecule determinations. LC/MS/MS is applicable to steroid measurements, testing for inborn errors of metabolism, and toxicology testing, particularly for therapeutic drug monitoring and pain management.

    For women, children, and hypogonadal males, in whom we expect very low testosterone concentrations, the advantages of LC/MS/MS technology are very important. LC/MS/MS can separate out interfering and structurely similar compounds. Direct immunoassays can suffer significant cross-reactivity from testosterone-like compounds, causing erroneous results. Therefore, they are not recommended for low level testosterone quantitation. In 2007, the Endocrine Society recommended use of extraction and chromatography followed by either immunoassay or mass spectrometry for measuring low testosterone concentrations. Direct immunoassays, however, are still suitable for measuring testosterone levels in adult males, in whom the levels are expected to be higher. In addition, immunoassays have typically a faster turnaround time.

    Question 5. Can our LC/MS/MS test measure testosterone and epitestosterone separately?
    Most healthy males have a testosterone to epitestosterone ratio of about 1:1. Since exogenous administration of testosterone does not affect epitestosterone levels in the body, the ratio of testosterone to epitestosterone has been used to identify athletes who might be using illegal anabolic steroids. Epitestosterone may potentially interfere with LC/MS/MS determinations. Therefore, we designed our assay to separate epitestosterone from testosterone. We do NOT measure or report epitestosterone in our current LC/MS/MS testosterone method. If an epitestosterone measurement is required, we suggest you approach a testing site that uses a World Anti-doping Agency (WADA)-approved assay.

    Total Testosterone, LC/MS/MS