Novel Biosensor for Detection of Endotoxin

Abstract. Bacterial endotoxins are components of the outer cell membranes of gram-negative organisms and is one of the most potent human toxins. Due to the health dangers associated with endotoxin contamination, testing is critical for pharmaceuticals, biological products, and medical devices. The majority of endotoxin testing still relies on the Limulus Amebocyte Lysate (LAL) assays using an extract from the blood of the horseshoe crabs. This decades-old technology threatens a limited biological resource, which is considered vulnerable by international organizations. We seek to enable the design of new endotoxin sensors with no requirement for horseshoe crab blood or any of its components. In addition, unlike typical analytical assays composed of multiple biological components and often complicated assay steps, our one-step lucCage biosensor can eliminate many complexities of existing assays as it is a "single-step, all-in-solution" assay. Our approach will be enabled through the (i) computational design and experimental selection of functional LPS bioluminescent biosensors; (ii) in vitro evolution of biosensors to optimize sensitivity and stability; and (iii) optimization of the LPS detection assay conditions and formulation of a 96-well kit. With our proprietary technology, we can develop alternative de novo protein endotoxin biosensors that provide multiple advantages over current techniques: (i) sensitivity by using bioluminescent readouts over turbidimetric, colorimetric or fluorescent readouts, (ii) broad dynamic range in a single test that will reduce the total number of tests required by the user to quantify endotoxin in a sample, (iii) stability and cost, as our biosensor proteins are highly stable and easy to manufacture. Thus, successful development of endotoxin sensing lucCage biosensors will enable the development of sustainable, inexpensive, and robust endotoxin bioassays of high impact in the biotechnology industry.