Overcoming the Effects of Matrix Interference in the Measurement of Urine Protein Analytes

Abstract

Using multiplex bead assays to measure urine proteins has a great potential for biomarker discovery, but substances in urine (the matrix) can interfere with assay measurements. By comparing the recovery of urine spiked with known quantities of several common analytes, this study demonstrated that the urine matrix variably interfered with the accurate measurement of low abundance proteins. Dilution of the urine permitted a more accurate measure of these proteins, equivalent to the standard dilution technique when the diluted analytes were above the limits of detection of the assay. Therefore, dilution can be used as an effective technique for over-coming urine matrix effects in urine immunoassays. These results may be applicable to other biological fluids in which matrix components interfere with assay performance.

A novel sensor based on electrodeposited Au–Pt bimetallic nano-clusters decorated on graphene oxide (GO)–electrochemically reduced GO for sensitive detection of dopamine and uric acid

“…In contrast to the sensor previously reported [100], the optimized assay was able to detect endogenous DA or UA in un-diluted serum samples. But some literature has suggested that larger peaks which displayed higher DA or UA concentrations were not linear in the whole sample without or less dilution [99,[101][102]. These reported suggested that interference due to serum complicated composition (especially ascorbic acid) was proportionally higher for less diluted samples, which was in accordance with the results described by other authors.…”

Endothelial Nitric Oxide Synthase Reduces Crescentic and Necrotic Glomerular Lesions, Reactive Oxygen Production, and MCP1 Production in Murine Lupus Nephritis

“…Urine was diluted 1∶10 to reduce interference from the urine matrix [16]. Measurements were performed in triplicate.…”

Analytical Performance of ELISA Assays in Urine: One More Bottleneck towards Biomarker Validation and Clinical Implementation

“…For urine, a diluent of phosphate buffered saline is recommended for use; however this does not resolve the issue of variability of urine matrix components as the measurements appear less stable compared to those in serum and plasma. [ 28 ] To our knowledge the only urinary protein measured by ELISA in clinical laboratories is albumin. [ 4 ]…”

“…High variability was observed in protein recovery in the urine samples even between assays indicating that matrix components differ among urine samples and also highlighting their ability to variably interfere in accurate protein measurement. [ 28 ]…”