Automated immunoassay system for AFP-L3% using on-chip electrokinetic reaction and separation by affinity electrophoresis.
Implementation of the on-chip immunoassay for alpha-fetoprotein (AFP)-L3% was achieved using a fully automated microfluidic instrument platform that will prepare the chip and run the assay with a total assay time of less than 10min. Reagent/sample mixing, concentration, and reaction in microfluidic channels occur by the electrokinetic analyte transport assay (EATA) technique, enabling the integration of all assay steps on-chip. The determination of AFP-L3%, a biomarker for hepatocellular carcinoma, was achieved by the presence of Lens culinaris agglutinin in the separation channel, causing separation of the fucosylated isoform, AFP-L3, from the nonfucosylated AFP-L1 by lectin affinity electrophoresis. Laser-induced-fluorescence (LIF) detection was used to quantitate the labeled immunocomplexes. The limit of detection (LOD) was 0.1ng/ml AFP, and assay precision of less than 2% coefficient of variation (CV) was obtained for quantitation from 24 to 922ng/ml total AFP in spiked serum samples. Assay precision of less than 3% CV was obtained for AFP-L3% measurements from 8.5 to 81%. Furthermore, good correlation of test results for 68 patient serum samples with a commercially available reference method (LiBASys assay for AFP-L3%) was obtained, with r(2)=0.981 and slope=1.03.
Kagebayashi
Chiaki
C
Osaka Research Laboratory, New Diagnostics Business and Technology Development Department, Wako Pure Chemical Industries Ltd., 6-1 Takada-cho, Amagasaki, Hyogo Prefecture, Japan.
Yamaguchi
Isao
I
Akinaga
Ayumi
A
Kitano
Hiromichi
H
Yokoyama
Kazunori
K
Satomura
Masahiro
M
Kurosawa
Tatsuo
T
Watanabe
Mitsuo
M
Kawabata
Tomohisa
T
Chang
William
W
Li
Chen
C
Bousse
Luc
L
Wada
Henry G
HG
Satomura
Shinji
S
D006528:Carcinoma, Hepatocellular / Q000175:diagnosis; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D046210:Microfluidic Analytical Techniques; D015203:Reproducibility of Results; D000509:alpha-Fetoproteins / Q000032:analysis*
D000509:alpha-Fetoproteins