YOUR SCREEN DOESN’T MATCH THE CONFIRMATION
Endogenous compounds in real patient urine inhibit some β-glucuronidases far more than others. IMCSzyme RT is 8-10x more resistant to these inhibitors
THE PROBLEM WITH SYNTHETIC CONTROLS
Method validation typically relies on drug-free urine fortified with known concentrations of glucuronidated analytes. Drug-free urine is a matrix that behaves predictably. Unfortunately, real patient samples are not as straightforward.
Naturally occurring compounds in human urine (e.g., urea, vitamins, and dietary flavonoids) inhibit β-glucuronidase activity in ways that spiked controls do not replicate. The effect varies by enzyme and by analyte, which means a method that passes validation on fortified urine can fail to detect analytes in real patient samples. This greatly increases the risk of false negatives in urine drug testing.
WHAT THE DATA SHOWS
In a study of 90 unfortified patient urine samples screened for oxymorphone, IMCSzyme RT and a competing enzyme were run side by side at the same enzyme volume using the same 15-minute room temperature protocol. Thirty-three samples tested positive with IMCSzyme RT but negative with Enzyme B. This suggests Enzyme B may have given 33 false negatives.
A second study expanded the comparison to 96 patient samples across four opioids: morphine, oxymorphone, hydromorphone, and codeine. Hydromorphone showed 25 results in disagreement, 16 for oxymorphone, five for codeine, and three for morphine. Across all four analytes, samples hydrolyzed with IMCSzyme RT tested positive while those tested with Enzyme B were negative.
Across both studies, no sample that tested positive with the competing enzyme tested negative with IMCSzyme RT.
WHY IMCSZYME RT HOLDS UP IN REAL SAMPLES
IMCSzyme RT is a genetically modified, multi-enzyme blend formulated to perform across a broad substrate range and resist the inhibitory compounds found in clinical urine samples. It has been recently demonstrated that IMCSzyme RT shows 8-10x greater resistance to endogenous inhibitors compared to single-enzyme competitors.
