(276d) Dielectrophoretic Separation of Mouse Ovarian Surface Epithelium Cells

Ovarian cancer is the leading cause of gynecologic cancer deaths in women in the United States. Every year, over 20,000 women are diagnosed with this cancer, and over 15,000 women die. The 5-year survival rate for women diagnosed in the early stages is 70-90%, but that for women diagnosed in the advanced stages is 20%. 80-90% of the patients with advanced disease do initially respond to chemotherapy, but 85-90% will relapse, resulting in a survival rate of 20-25%. Yet, symptoms of ovarian cancer typically do not arise until it is in the late stages, so detection methods are currently being developed to be able to identify this disease when it is in its early stages.

A challenge in current screening techniques is that invasive methods such as laparoscopy and laparotomy are necessary. Due to the low incidence of this cancer (40 per 1,000,000 per year), the danger of surgical complications for false-positive screenings outweighs the advantages for early detection in true-positive women, so screening test specificity must be a minimum of 99.6%. In addition to this, another challenge is to improve sensitivity so that ovarian cancer can be detected even before symptoms arise.

The most popular biomarker for study in screening methods is CA-125. Elevated levels of this biomarker are found in 50% of early stage patients and 90% of late stage patients. Additional techniques include the use of ultrasound to detect morphological changes in the ovary, as well as color-flow Doppler imaging to track changes in blood-flow patterns. Attempts to combine these techniques do improve sensitivity, but somewhat decrease specificity.

Miniaturized systems represent an attractive alternative for clinical analysis due to portability, rapid response time and reduced requirement of sample and reagents. Dielectrophoresis, a non destructive electrokinetic transport mechanism, is one of the most employed techniques for the manipulation of cells in microdevices. In this study the application of contactless DEP (cDEP) and insulator-based DEP (iDEP) for the separation and concentration of cells is presented. Microdevices with multiple sections were employed to achieve simultaneous concentration and separation of early and late stages of Mouse Ovarian Surface Epithelium (MOSE) cells, and differentiation of MOSE cells from OP9 (fibroblast) and PC1 (macrophages) cells in sample of peritoneal fluid for ovarian cancer diagnosis. The results demonstrated that the combination of cDEP and iDEP techniques offer a great potential for cancer diagnosis.