Chemiluminescent immunoassay (CLIA) for urinary albumin

Abstract

A simple chemiluminescent immunoassay (CLIA) for urinary albumin has been developed based on the use of a chemiluminescent acridinium ester-labelled human albumin and a commercially available antiserum. It includes two incubation steps and a second polyethylene glycol-assisted antibody separation. The sensitivity of detection is 0.016 mg/l, the assay working range is 0.1-5 mg/l, and the inter-assay CVs are less than or equal to 15%. Using 10- and 50-fold sample dilutions in assay buffer, a wide working range (1-250 mg/l) is obtained covering normal and pathological conditions. Timed overnight urine samples (bed rest conditions) were collected on three consecutive days for each patient. Albumin excretion rate (AER) was 4.7 +/- 2.7 micrograms/min (mean +/- SD), range 1-15.9 micrograms/min in 36 healthy subjects (17 male, 19 female, ages 4-56 years), with day-to-day variations of 28.5 +/- 20% (mean +/- SD), range 3.3-76.1%. The use of an acridinium ester as a chemiluminescent (CL) label overcomes the disadvantages of short shelf-life and health and safety hazards associated with radioisotopes. Results compare favourably with those obtained using a commercially available RIA kit.

A silicon nitride ion sensitive field effect transistor‐based immunosensor for determination of urinary albumin

“…Therefore, urinary microalbumin has been proposed as an early sign of kidney damage in people who have a risk of chronic kidney disease and cardiovascular disease in nondiabetic individuals 6 . There are many methods that have been proposed to determine the amount of albumin in urine such as enzyme‐linked immunosorbent assay (ELISA), 7 fluorescence, 8,9 immunoturbidimetry (IT), 10,11 immunonephelometry (IN), 12 radioimmunoassay (RIA), 13 and chemiluminescence immunoassay (CLIA) 14,15 . Although these methods are high sensitivity and specificity, they have some limitations such as health hazards, being time‐consuming, labor‐intensive protocols, and requiring experienced technicians.…”

“…6 There are many methods that have been proposed to determine the amount of albumin in urine such as enzyme-linked immunosorbent assay (ELISA), 7 fluorescence, 8,9 immunoturbidimetry (IT), 10,11 immunonephelometry (IN), 12 radioimmunoassay (RIA), 13 and chemiluminescence immunoassay (CLIA). 14,15 Although these methods are high sensitivity and specificity, they have some limitations such as health hazards, being time-consuming, labor-intensive protocols, and requiring experienced technicians. Thus, several sensor methods have been developed as a simple method to determine the amount of HSA such as quartz crystal microbalance (QCM), 16,17 electrochemical sensor, [18][19][20] magnetoelastic biosensor, 21 microfluidic devices, 22,23 surface-enhanced Raman scattering (SERS), 24 and so on.…”