Simultaneous Multiple Immunoassays in a Compact Disc-Shaped Microfluidic Device Based on Centrifugal Force

• Published in: Clinical chemistry (Baltimore, Md.) Md.), 2005-10, Vol.51 (10), p.1955-1961
• Main Authors: Honda, Nobuo, Lindberg, Ulrika, Andersson, Per, Hoffmann, Stephan, Takei, Hiroyuki
• Format: Article
• Language: English
• Subjects: alpha-Fetoproteins - analysis; Analytical, structural and metabolic biochemistry; Animals; Antibodies; Antibodies - analysis; Antigens; Biological and medical sciences; Carcinoembryonic Antigen - analysis; Cattle; Centrifugation; Comparative studies; Detection limits; Flow rates; Fluorescence; Fundamental and applied biological sciences. Psychology; Immunoassay; Immunoassay - methods; Immunoassays; Interleukin-6 - analysis; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Microfluidic Analytical Techniques - instrumentation; Microfluidic Analytical Techniques - methods; Reagents; Sensitivity and Specificity; Serum Albumin, Bovine - analysis; Work stations
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1373/clinchem.2005.053348

We explored the potential of a microfluidic device based on centrifugal force as an immunoassay platform by examining the imprecision of assays carried out with 200 nL of sample. Biotinylated antibodies against alpha-fetoprotein (AFP), interleukin-6 (IL-6), and carcinoembryonic antigen [(CEA); 0.1 g/L each in 15 mmol/L phosphate-buffered saline (PBS) containing 0.1 mL/L Tween 20] were attached to a microcolumn packed with streptavidin-coated particles. A 200-nL sample was then allowed to pass through the microcolumn for 240 s, followed by Alexa 647-labeled detection antibody (7.5 mg/L in 15 mmol/L PBS containing 10 g/L bovine serum albumin). The flow rate was controlled by altering the rotational speed. Up to 104 sandwich type immunoassays were completed within 50 min. For AFP, IL-6, and CEA the detection limits were, respectively, 0.15, 1.25, and 1.31 pmol/L. Inter- and intraassay imprecisions (CVs) were