Conjugation of biomolecules with magnetic protein microspheres for the assay of early biomarkers associated with acute myocardial infarction.
This study demonstrates an improved magnetic protein microsphere-aided sandwich fluoroimmunoassay for the analysis of myoglobin and heart-type fatty acid binding protein (H-FABP), early protein markers associated with acute myocardial infarction. In preparation for the assay we constructed superparamagnetic human serum albumin (HSA)/gamma-Fe(2)O(3) microspheres, and grafted capture antibodies (monoclonal antimyoglobin 7C3 and anti-H-FABP 10E1) onto the protein microspheres using the avidin-biotin system. Then the antibody-carrying microspheres were used in a sequential sandwich fluoroimmunoassay along with detection antibodies (Alexa fluor594-labeled antimyoglobin 4E2 and FITC-labeled anti-H-FABP 9F3). The magnetic HSA/gamma-Fe(2)O(3) microspheres were characterized by scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectrophotometry, atomic absorption spectrophotometry, and vibrating sample magnetometry. Fluorescence images of the post-immunoassay microspheres recorded using an inverted fluorescence 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 semiquantitatively detect both myoglobin and H-FABP. The detection limit was 10 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, P.R. China. jywang@nwsuaf.edu.cn
Wang
Xueqin
X
Ren
Li
L
Wang
Qiang
Q
Li
Li
L
Liu
Wenming
W
Wan
Zongfang
Z
Yang
Linyan
L
Sun
Peng
P
Ren
Lili
L
Li
Manlin
M
Wu
Heng
H
Wang
Jinfeng
J
Zhang
Lei
L
D015415:Biomarkers / Q000097:blood*; D042241:Early Diagnosis; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000097:blood*; D005290:Ferric Compounds / Q000737:chemistry; D015200:Fluoroimmunoassay; D006801:Humans; D057230:Limit of Detection; D008280:Magnetics; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis*; D009211:Myoglobin / Q000097:blood*; D011379:Prognosis
D015415:Biomarkers; C493408:FABP3 protein, human; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins; D005290:Ferric Compounds; D009211:Myoglobin