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.