{"id":6063,"date":"2012-07-18T22:26:22","date_gmt":"2012-07-18T22:26:22","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/?p=6063"},"modified":"2012-07-18T22:26:22","modified_gmt":"2012-07-18T22:26:22","slug":"iso-dielectric-separation-of-cells-and-particles","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/iso-dielectric-separation-of-cells-and-particles\/","title":{"rendered":"Iso-dielectric Separation of Cells and Particles"},"content":{"rendered":"

The development of new techniques to separate and characterize cells with high throughput has been essential to many advances in biology and biotechnology.\u00a0 We are developing a novel method for the simultaneous separation and characterization of cells based upon their electrical properties.\u00a0 This method, iso-dielectric separation (IDS), uses dielectrophoresis (the force on a polarizable object [1<\/a>] <\/sup> ) and a medium with spatially varying conductivity to sort electrically distinct cells while measuring their effective conductivity (Figure 1).\u00a0 It is similar to iso-electric focusing except that it uses DEP instead of electrophoresis to concentrate cells and particles to the region in a conductivity gradient where their polarization charge vanishes [2<\/a>] <\/sup> [3<\/a>] <\/sup> [4<\/a>] <\/sup>.<\/p>\n

Sepsis is a clinical condition caused by infection; despite state-of-the-art facilities and treatments, sepsis has a mortality rate of ~30%. Sepsis induces inflammation and organ failure and a possible treatment would require removing inflammatory agents from whole blood such as activated neutrophils. Using an automated IDS system (see Figure 2a) we could see electrical differences between white and red blood cells (Figure 2b). Furthermore, we measured the electrical properties of activated vs. non-activated neutrophils (see Figure 2c). The populations show differences that indicate that the populations are amenable to efficient separation. Using the position as a classifier to determine if a neutrophil is activated or non-activated yields receiver operating characteristic (ROC) curves with high area-under-curve (AUC), which would result in good specificity (see Figure 2d).<\/p>\n\n\t\t