Superparamagnetic microsphere-assisted fluoroimmunoassay for rapid assessment of acute myocardial infarction.
Rapid assessment of acute myocardial infarction (AMI) was successfully demonstrated using an improved superparamagnetic polymer microsphere-assisted sandwich fluoroimmunoassay to detect two early cardiac markers-myoglobin and human heart-type fatty acid binding protein (H-FABP). This assay used a preparation of superparamagnetic poly(styrene-divinylbenzene-acrylamide) microspheres, glutaraldehyde-coupled capture antibodies (monoclonal anti-myoglobin 7C3 and anti-H-FABP 10E1) grafted onto the polymer microspheres, and a sequential sandwich fluoroimmunoassay using detection antibodies (FITC-labeled anti-myoglobin 4E2 and FITC-labeled anti-H-FABP 9F3). Characterization of the polymer microspheres by TEM, SEM and Fourier transform infrared spectroscopy (FT-IR) showed that the microspheres were uniformly round with an average diameter of 1.12 microm, and had a Fe(3)O(4)-polymer core-shell structure (shell thickness was about 84 nm) with 0.22 mmol/g amino groups on their surfaces. The magnetic behavior of the Fe(3)O(4)-polymer microspheres was superparamagnetic (M(s)=13 emu/g, H(c)=13.1 Oe). Fluorescence images of the post-immunoassay microspheres recorded using a confocal laser-scanning microscope showed that the average fluorescence intensity was correlated with the concentration of cardiac markers, in agreement with the results obtained by an F-4500 FL spectrophotometer; this indicated that the fluoroimmunoassay could be used to semi-quantitatively detect both myoglobin and H-FABP. The detection limit was 25 ng/mL for myoglobin and 1 ng/mL for H-FABP.
Wang
Jinyi
J
College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China. jywang@nwsuaf.edu.cn
Ren
Li
L
Wang
Xueqin
X
Wang
Qiang
Q
Wan
Zongfang
Z
Li
Li
L
Liu
Wenming
W
Wang
Xuming
X
Li
Manlin
M
Tong
Dewen
D
Liu
Ajing
A
Shang
Bingbing
B
D015415:Biomarkers / Q000097:blood; D001774:Blood Chemical Analysis / Q000379:methods; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000097:blood*; D005290:Ferric Compounds; D015200:Fluoroimmunoassay / Q000379:methods*; D006801:Humans; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D009211:Myoglobin / Q000097:blood*; D011137:Polystyrenes
D015415:Biomarkers; C493408:FABP3 protein, human; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins; D005290:Ferric Compounds; D009211:Myoglobin; D011137:Polystyrenes; C000499:ferric oxide