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14th International AIDS ConferenceBarcelona, Spain — July 7-12, 2002 |
Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. WeOrB1343
BACKGROUND: Although the costs of HIV drugs have been reduced in parts of the developing world, the costs of HIV laboratory tests remain high, and make the establishment of treatment programs problematic. Affordable HIV diagnostics that could be performed at regional and local health centers in developing countries are urgently needed, particularly CD4 counts and HIV RNA levels. We have applied microchip technology to the development of affordable and practical HIV diagnostic tests.
METHODS: Agarose microbeads (<250 µm diameter) were covalently coated with molecules to detect HIV Ab, p24 Ag, HIV RNA and CD4 cells, and placed in the wells of stamp-sized silicon microchips. Serum samples were processed on the microchips, and HIV Ab, p24 Ag, HIV RNA or CD4 cells bound to the beads were detected by transmitted light or fluorescent signals collected on a video CCD chip interfaced with the detection chip. Signals were processed by image analysis software contained in the detection device. Results were compared with standard ELISA, PCR or flow cytometry-based assays.
RESULTS: HIV Ab and p24 Ag in serum samples can be detected by this automated microchip system with sensitivity equal to or better than standard ELISA assays.
Fig 1. CD4 cells bound to beads detected by a) transmitted light or b) fluorescence.
Fig 2. Serum containing both HBV Ab and HIV-1 Ab at titers of 1:200 detected on a microchip.
Preliminary studies suggest that microchip-based assays for HIV RNA detection and CD4 cell count are also feasible.
CONCLUSIONS: Microchip-based detection of HIV Ab, p24 Ag, RNA and CD4 counts are feasible. These tests may be combined on a single disposable and inexpensive microchip. A battery-powered, hand-held chip reader has also been developed. Microchip-based HIV diagnostics could make affordable laboratory testing in resource-poor settings a possibility.
Presenting author: W R Rodriguez
1Massachusetts General Hospital, Partners AIDS Research Center, Massachusetts General Hospital, 149 13th Street, Rm 5234, Charlestown, MA 02129, United States
2University of Texas, Austin, United States
020708
WeOrB1343
Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.
