|
|
||||||||
1 Department of Biotechnology, University of Turku, Tykistökatu 6, 20520 Turku, Finland.
2 Central Laboratory of Turku University Hospital, Kiinamyllynkatu 4-8, 20521 Turku, Finland.
aAuthor for correspondence. Fax 358-2-3338050; e-mail qiqin{at}utu.fi.
Background: Microalbuminuria is an established early marker of diabetic nephropathy and an important cardiovascular risk factor in diabetes and hypertension. We aimed to develop a rapid point-of-care assay for the measurement of urine albumin.
Methods: The competitive homogeneous assay used an albumin-specific monoclonal antibody labeled with a stable fluorescent europium chelate as donor and an albumin labeled with cyanine 5 (Cy5) as acceptor. The assay was performed at room temperature in single microtitration wells that contained all the required dry-form reagents. The close proximity between the two labels in the immune complex allowed fluorescence resonance energy to be transferred from the pulse-excited europium chelate to the acceptor Cy5. The emission of long-lived energy transfer signal from the sensitized Cy5 was measured at 665 nm with time-resolved fluorometry that eliminated short-lived background.
Results: The assay procedure required 12 min for a 10-µL urine sample. The working range was from 10 to
320 mg/L, and the lower limit of detection was 5.5 mg/L. The within- and between-run CVs were 6.910% and 7.513%, respectively. Recovery was 103122%. The assay correlated well (r2 = 0.98; n = 37) with a laboratory-based immunoassay, although mean (SD) results were 7 (29)% lower.
Conclusions: The speed and ease of performance of this assay recommend it for near-patient use. The assay is the first to combine a fluorescence resonance energy transfer-type rapid competitive assay with an all-in-one dry reagent.
The following articles in journals at HighWire Press have cited this article:
![]() |
J. R. Lakowicz, J. Malicka, E. Matveeva, I. Gryczynski, and Z. Gryczynski Plasmonic Technology: Novel Approach to Ultrasensitive Immunoassays Clin. Chem., October 1, 2005; 51(10): 1914 - 1922. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |