Counting White Blood Cells at Home

Yu-Chong Tai, Professor of Electrical Engineering and Mechanical Engineering, and colleagues have developed a portable device to count white blood cells that needs less than a pinprick's worth of blood and takes just minutes to run. The heart of the new device is a 50-micrometer-long transparent channel made out of a silicone material with a cross section of only 32 micrometers by 28 micrometers—small enough to ensure that only one white blood cell at a time can flow through the detection region. The stained blood sample flows through this microfluidic channel to the detection region, where it is illuminated with a laser, causing it to fluoresce. [Caltech Release]