CTC-iChip (image) Massachusetts General Hospital Caption Antigen-independent cell sorting begins by tagging the white cells in a blood sample with magnetic beads. The sample is then passed into the CTC-iChip microfluidic system, which first removes red cells, plasma and free magnetic beads and then sorts out tagged white blood cells, leaving a purified solution of circulating tumor cells. Credit Emre Ozkumur, Mass. General Hospital Center for Engineering in Medicine Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.