A sensitive, low-cost, fluorescence assay for determination of HIV p24 in infants

Period of Performance: 08/06/2014 - 01/31/2015


Phase 1 SBIR

Recipient Firm

Song Diagnostic Research, LLC
Woodside, CA 94062
Principal Investigator


DESCRIPTION (provided by applicant): Each year, 1.5 million children are born to mothers living with HIV resulting in vertical transmission of HIV to newborns in 350,000 cases. Early testing followed by prompt anti-retroviral therapy (ART) is known to save lives, yet lack of point-of-care (POC) tests for infants results in delays or absence of therapy. Our approach will provide a low-cost yet quantitative and sensitive lateral flow immunoassay (LFIA) test to analyze and quantitate the presence of HIV p24. Fluorescent dyes will be used to improve the limit of detection compared to existing rapid tests. A smart phone is utilized for imaging, analysis and automated reporting. A long Stokes shift dye, R-phycoerythrin (PE) will be used as the fluorescent reporter, either singly or bundled into a cluster. The optical properties of PE allow the use of an inexpensive illumination device;the minimal non-specific binding of PE results in sensitive detection with a wide dynamic range. Additional gains in sensitivity will be achieved through an integrated test feature designed to dissociate target protein immune-complexes for improved access by the test reagents. In Phase I we will: 1) Optimize the PE reporter (cluster) on anti-HIV p24 antibody; 2) Develop a smartphone application to allow automated analysis; 3) Develop an on-LFIA strip "zone of dissociation" to aid in analysis of complexed p24; 4) Develop the use of the control line as a quantification standard on the lateral flow strip to allow absolut quantitation of p24; 5) Design, fabricate and test a prototype of a low cost fluorescence system designed with a materials cost less than $35. 6) Validate the p24 LFIAs by comparing results with commercially available ELISA and LFIA tests using heat inactivated serum spiked with recombinant HIV p24. These investigations will demonstrate the performance advantage of our system for detection and analysis of HIV p24. For phase II we hope to test authentic patient samples.