Lab-on-a-chip. Technician pumping blood from a syringe into a lab-on-a-chip designed to detect T-cells (lymphocytes) that express the protein CD4. HIV, the virus that causes AIDS, attacks cells containing CD4 and the onset of full-blown AIDS can be measured by a dramatic reduction in CD4 carrying T-cells. This lab-on-a-chip, created by biomedical engineer Mehmet Toner could one day be used as an accurate, reliable and cheap method to monitor the blood of HIV patients. Photographed in 2009.