Development of Indigenous Bio-sensing Methodology for Rapid and LowCost Endotoxin Detection System

Abstract

Endotoxin is a signature molecule of gram-negative bacteria and is clinically significant as the agent of gramnegative sepsis, a disease condition with high mortality. This study describes an enzyme-substrate reaction using the distilled water lysate of the granular hemocytes (amebocytes) of the mangrove horseshoe crab (Tachypleus gigas), a native of the Bay of Bengal, and a chromogenic peptide which results in the production of yellow spectroscopically monitored product in the presence of endotoxin. The assay is complete within 30 min and shows a lower detection limit of 0.2 EU/mL. The novelty of our approach is the use of mangrove horseshoe crabs are the source of amebocyte lysate instead of the American horseshoe crab (Limuluspoly phemus).The anticipated methodology offers advantages for the South Asian market that include a low cost due to use of indigenous reagents. This method shows exquisite sensitivity and provides a rapid assessment of LPS concentrations. We assume that the commercial development of our assay will reduce the cost of a single chromogenic endotoxin detection test as compared to the cost of present imported kits presently available in Asian and Indian market.