Detection of protective antigen, an anthrax specific toxin in human serum by using surface plasmon resonance

作者：Ghosh Neha; Gupta Nidhi; Gupta Garima; Boopathi Mannan; Pal Vijay; Goel Ajay Kumar^*

来源：Diagnostic Microbiology and Infectious Disease, 2013, 77(1): 14-19.

DOI：10.1016/j.diagmicrobio.2013.05.006

• Anthrax
• Bacillus anthracis
• Monoclonal antibody
• Protective antigen
• Surface plasmon resonance

In this study, surface plasmon resonance (SPR) technology was used for the sensitive detection of protective antigen (PA), an anthrax specific toxin in spiked human serum samples. A monoclonal antibody raised against Bacillus anthracis PA was immobilized on carboxymethyldextran-modified gold chip, and its interaction with PA was characterized in situ by SPR. By using kinetic evaluation software, K-D (equilibrium constant) and B-max (maximum binding capacity of analyte) were found to be 20 fM and 18.74 m degrees, respectively. The change in Gibb's free energy (Delta G= -78.04 kJ/mol) confirmed the spontaneous interaction between antigen and antibody. The assay could detect 1 pg/mL purified PA. In PA-spiked human serum samples, 10 pg/mL of PA could be detected. Presence of PA in blood samples serves as an important early diagnostic marker for B. anthracis infections. Thus, SPR test can be a sensitive assay for detection of anthrax at early stages of infection.

• 出版日期2013-9