A Rapid Flow through Membrane Enzyme Linked Immunosorbent Assay for Bacillus anthracis using Surface Array Protein as a Biomarker

Anthrax, caused by Bacillus anthracis is an important disease of biowarfare and public health importance. It is imperative to develop a simple system which can detect and differentiate B. anthracis from other closely related species. The surface array protein (Sap), which is secreted during the early growth phase of bacteria can be an important biomarker for detection of B. anthracis. In the present study, we have developed a rapid flow through membrane ELISA for detection of B. anthracis. Polyclonal antibodies were used to develop a sandwich plate ELISA, which could detect 3.9 ng/ml of recombinant Sap. B. anthracis bacteria grown in culture broth could be detected after 5 h of growth. Finally, a rapid flow through membrane ELISA was developed which can be accomplished just within 2 minutes, instead of 3-4 h as required in sandwich plate ELISA. The results established that the developed flow through membrane ELISA may be used for detection of B. anthracis. The proposed method is rapid, safe and user friendly for detection of B. anthracis culture.