SBIR-STTR Award

This Small Business Innovation Research Phase I project is designed to develop methods to chemically modify small peptide molecules for use primarily in non-radioactive, rapid, sensitive chemiluminescent immunoassays. Assay Designs, Inc. would like to replace the lengthy, complex radioactive immunoassays for small peptides with a rapid assay, reducing the incubation time from several days to a few hours. The research project will investigate the possibility of attaching chemiluminescent molecules to the N-terminal amino acid of a small peptide, and determining the effect of the change on the immunological binding. Several approaches are proposed to achieve this derivatization of the peptide. Researchers have chosen the neurologically active peptide, vasopressin as a suitable trial peptide. Current assay methods require the use of radioactive materials in procedures that take several days to complete. The purpose of this Phase I research is to test feasibility in chemically modifying vasopressin to attach chemiluminescent molecules that allow for rapid sensitive detection. The methods used will involve the attachment of chemiluminescent Acridinium esters and alkaline phosphatase systems to these small peptides. Researchers will also investigate small changes to the peptide sequence in order to allow easier introduction of such chemiluminescent molecules and labels. The methods used to chemically alter these peptides should be applicable to a large number of different small peptide molecules.

This Small Business Innovation Research Phase II project will further develop ways to replace radioactivity for small peptide immunoassays using chemiluminescence detection methods. The concentration of small peptides in biological samples are normally measured using bioassays or by radioimmunoassay methods. Bioassays tend to be inaccurate and cumbersome to perform, while radioimmunoassays use '251 labeled peptides as a detection method. The cost, handling, environmental, stability and sensitivity concerns of using i25I for these assays makes alternative detection systems attractive. In Phase I we demonstrated that chemiluminescence can be applied to measure a small peptide, vasopressin, with speed and sensitivity. We managed to make stable conjugates of vasopressin that demonstrated increased speed and sensitivity. The chemical methods demonstrated in Phase I have to be further developed and refined. The use of peptide analogs for use in raising antisera and also for conjugation to chemiluminescent detection systems need to be further tested. We were able, using analogs of vasopressin, to synthesize conjugates that have better binding and sensitivity in the assay. We wish to explore the possibility of raising antisera to immunogens using these and similar peptide analogs. We believe that the use of these analogs, where the conjugation position has been chosen to be chemically isolated from the native peptide, may yield antisera with better specificity and reactivity. Assay designs is a company with a proven, track record of developing, marketing and selling novel immunoassay test kits using chemiluminescence. We advertise in national scientific magazines on a regular basis and have distributors in Japan and in Austria, Germany and Switzerland. The applications of chemiluminescence technology to the measurement of analyses where the only sensitive, reproducible methods are radioactive have tremendous potential. The concerns with the use and disposal of HI make chemilumi nescence the method that can replace this RIA system and improve the sensitivity and speed of these assays. One RLA manufacturer has 139 different kits selling for up to $450 per kit. The market for non-radioactive kits with the advantages of speed and sensitivity is substantial