CD4 cell isolation from blood using finger-actuated on-chip magnetophoresis for rapid HIV/AIDS diagnostics

With timely diagnosis and correct treatment, people living with HIV/AIDS can consider the disease as a chronic rather than a terminal illness. Still, in regions were HIV is endemic, rapid diagnosis is a challenge due to the complexity of the instrumentation required, the poor infrastructure in these countries, as well as the technical expertise required to carry out the diagnosis. This paper presents a microfluidic chip based approach allowing semiquantitative CD4+ cell counting on a cheap, rapid, highly portable and instrumentation-free Point-of-Care HIV diagnostic device. Flow is driven by finger-pressing a flexible reservoir, and the target cells are immobilized through magnetophoresis. The fluidic test completes within ca. 30 seconds of sample application to the chip.