Method and apparatus for performing contactless optically-induced dielectrophoresis for separation of circulating tumor cells
A method for performing contactless ODEP for separation of CTCs is provided with the steps of obtaining patients' blood with rare cell suspected CTCs; adding at least one fluorescent antibody binding to CTCs into the blood; staining the blood; injecting the stained blood with fluorescent dye into an ODEP device and then performing fluorescent image identification; trapping the CTCs with at least one fluorescent antibody in the ODEP device by creating an image pattern and then generating an ODEP force; Separating the trapped CTCs from other non-CTCs cells; absorbing the trapped CTCs; and obtaining a high purity of CTCs. An apparatus for performing contactless ODEP for separation of CTCs is also provided.
1. A method for performing contactless optically-induced dielectrophoresis (ODEP) for separation of circulating tumor cells (CTCs), the method comprising the steps of:
(1) obtaining blood with suspected CTCs;
(2) adding at least one fluorescent antibody that binds to the CTCs into the blood to form stained blood;
(3) injecting the stained blood with the at least one fluorescent antibody into a sample receiving member of an ODEP device wherein the ODEP device includes a first conductive glass and a second conductive glass, the first conductive glass includes a transverse main channel and a longitudinal micro channel joining the main channel at a cell separation zone, and the first conductive glass includes a first hole and a second hole aligned with two ends of the main channel respectively, a third hole aligned with one end of the microchannel that is distal to the cell separation zone, the sample receiving member disposed on and aligned with the first hole, an exhaust discharge member disposed on and aligned with the second hole, a target collection member disposed on and aligned with the third hole, and a controller including an optical projection device and an image fetch device;
(4) performing fluorescent image identification by immunofluorescent microscopic observation using the optical projection device and the image fetch device to identify and distinguish the CTCs bound to the at least one fluorescent antibody from pseudo positive target cells that have fluorescent expression and lack cell nuclei;
(5) trapping the identified CTCs bound to the at least one fluorescent antibody in the ODEP device by creating an image pattern by projecting a light image and then generating an ODEP force;
(6) separating the trapped CTCs from other non-CTCs at the cell separation zone;
(7) collecting the trapped CTCs in the target collection member; and
(8) obtaining the collected CTCs from the target collection member.
2. The method of claim 1 , wherein red blood cells (RBCs) and white blood cells (WBCs) are removed from the blood between step (1) and step (2).