Conjugation of biomolecules with magnetic protein microspheres for the assay of early biomarkers associated with acute myocardial infarction.

Abstract

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.

• Authors: Jinyi Wang, Xueqin Wang, Li Ren, Qiang Wang, Li Li, Wenming Liu, Zongfang Wan, Linyan Yang, Peng Sun, Lili Ren, Manlin Li, Heng Wu, Jinfeng Wang, Lei Zhang
• Journal: Analytical chemistry (Anal Chem) Vol. 81 Issue 15 Pg. 6210-7 (Aug 01 2009) ISSN: 1520-6882 [Electronic] United States
• PMID: 19555077 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• FABP3 protein, human
• Fatty Acid Binding Protein 3
• Fatty Acid-Binding Proteins
• Ferric Compounds
• Myoglobin

Topics

• Biomarkers (blood)
• Early Diagnosis
• Fatty Acid Binding Protein 3
• Fatty Acid-Binding Proteins (blood)
• Ferric Compounds (chemistry)
• Fluoroimmunoassay
• Humans
• Limit of Detection
• Magnetics
• Microscopy, Atomic Force
• Microscopy, Electron, Scanning
• Microspheres
• Myocardial Infarction (blood, diagnosis)
• Myoglobin (blood)
• Prognosis