Quantification of urinary albumin by using protein cleavage and LC-MS/MS.

ABSTRACT:

Background

Urinary albumin excretion is a sensitive diagnostic and prognostic marker for renal disease. Therefore, measurement of urinary albumin must be accurate and precise. We have developed a method to quantify intact urinary albumin with a low limit of quantification (LOQ).

Methods

We constructed an external calibration curve using purified human serum albumin (HSA) added to a charcoal-stripped urine matrix. We then added an internal standard, (15)N-labeled recombinant HSA ((15)NrHSA), to the calibrators, controls, and patient urine samples. The samples were reduced, alkylated, and digested with trypsin. The concentration of albumin in each sample was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and linear regression analysis, in which the rel

SUBMITTER: Seegmiller JC 

PROVIDER: S-EPMC3922069 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature