Membrane-based plasma collection device for point-of-care diagnosis of HIV.

A major requirement for the development of point-of-care tests for the detection of disease analytes is the need to separate plasma from whole blood in an efficient and rapid manner. Furthermore, the separated plasma must be able to elute efficiently the analyte of interest and serve effectively as a physical matrix to deliver the equivalent of neat plasma for downstream diagnostic analysis. Additionally, many applications require the use of heat shock to liberate immunocomplexed antigen found in the collected plasma.

p24 antigen rapid test for diagnosis of acute pediatric HIV infection.

Currently, the majority of HIV-infected infants are found within limited-resource settings, where inadequate screening for HIV due to the lack of access to simple and affordable point-of-care tests impedes implementation of antiretroviral therapy. Here we report development of a low-cost dipstick p24 antigen assay using a visual readout format that can facilitate the diagnosis of HIV for infants in resource-poor conditions. A heat shock methodology was developed to optimize disruption of immune complexes present in the plasma of infected infants.

Empirically optimized flow cytometric immunoassay validates ambient analyte theory.

Ekins' ambient analyte theory predicts, counterintuitively, that an immunoassay's limit of detection can be improved by reducing the amount of capture antibody. In addition, it also anticipates that results should be insensitive to the volume of sample as well as the amount of capture antibody added. The objective of this study was to empirically validate all of the performance characteristics predicted by Ekins' theory.

A lateral flow-based ultra-sensitive p24 HIV assay utilizing fluorescent microparticles.

The current demand for HIV diagnostic tests in resource-limited settings is not being fully addressed by the currently available nucleic acid test or enzyme-linked immunosorbent assay-based p24 antigen assays. This is primarily due to their high cost, their requirement for controlled laboratory conditions and/or personnel, or the relatively long turn-around time for test results. Self performing lateral flow assays address all of these issues but to date have not reached the level of analytical sensitivity for HIV p24 demonstrated by current generation enzyme-linked immunosorbent assay technology.