Scientific Publications by FDA Staff

J Acquir Immune Defic Syndr 2007 Oct 1;46(2):231-7

Nanoparticle-Based Biobarcode Amplification Assay (BCA) for Sensitive and Early Detection of Human Immunodeficiency Type 1 Capsid (p24) Antigen.

Tang S, Zhao J, Storhoff JJ, Norris PJ, Little RF, Yarchoan R, Stramer SL, Patno T, Domanus M, Dhar A, Mirkin CA, Hewlett IK

Tang SX (reprint author), US FDA, Ctr Biol Evaluat & Res, Mol Virol Lab, Bldg 29B,Rm 4NN16,8800 Rcokville Pike, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Mol Virol Lab, Bethesda, MD 20892 USA Nanosphere, N Brook, IL USA Univ Calif San Francisco, Blood Syst Res Inst, San Francisco, CA 94143 USA Univ Calif San Francisco, Dept Lab Med, San Francisco, CA 94143 USA Univ Calif San Francisco, Dept Med, San Francisco, CA USA NCI, Natl Inst Hlth, HIV & AIDS Malilgnancy Branch, Bethesda, MD 20892 USA Amer Red Cross, Biomed Serv Sci Support Off, Gaithersburg, MD USA US FDA, NCI, Interagcy Oncol Task Force, Bethesda, MD 20014 USA Northwestern Univ, Dept Chem, Evanston, IL USA Northwestern Univ, Int Inst Nanotechnol, Evanston, IL USA

Nanotechnology-based techniques are being widely evaluated in medical testing and could provide a new generation of diagnostic assays due to their high degrees of sensitivity, high specificity, multiplexing capabilities, and ability to operate without enzymes. In this article, we have modified a nanoparticle-based biobarcode amplification (BCA) assay for early and sensitive detection of HIV-1 capsid (p24) antigen by using antip24 antibody-coated microplates to capture viral antigen (p24) and streptavidin-coated nanoparticlebased biobarcode DNAs for signal amplification, followed by detection using a chip-based scanometric method. The modified BCA assay exhibited a linear dose-dependent pattern within the detection range of 0.1 to 500 pg/ml and was approximately 150-fold more sensitive than conventional enzyme-linked immunosorbent assay (ELISA). No false positive results were observed in 30 HIV-1- negative samples, while all 45 HIV-1 RNA positive samples were found HIV-1 p24 antigen positive by the BCA assay. In addition, the BCA assay detected HIV-1 infection 3 days earlier than ELISA in seroconversion samples. Preliminary evaluation based on testing a small number of samples indicates that the HIV-1 p24 antigen BCA may provide a new tool for sensitive and early detection of HIV-1 p24 antigen in settings where HIV-1 RNA testing is currently not routinely performed.