title: Rapid and label-free separation of Burkitt's lymphoma cells from red blood cells by optically-induced electrokinetics.
abstract: Early stage detection of lymphoma cells is invaluable for providing reliable prognosis to patients. However, the purity of lymphoma cells in extracted samples from human patients' marrow is typically low. To address this issue, we report here our work on using optically-induced dielectrophoresis (ODEP) force to rapidly purify Raji cells' (a type of Burkitt's lymphoma cell) sample from red blood cells (RBCs) with a label-free process. This method utilizes dynamically moving virtual electrodes to induce negative ODEP force of varying magnitudes on the Raji cells and RBCs in an optically-induced electrokinetics (OEK) chip. Polarization models for the two types of cells that reflect their discriminate electrical properties were established. Then, the cells' differential velocities caused by a specific ODEP force field were obtained by a finite element simulation model, thereby established the theoretical basis that the two types of cells could be separated using an ODEP force field. To ensure that the ODEP force dominated the separation process, a comparison of the ODEP force with other significant electrokinetics forces was conducted using numerical results. Furthermore, the performance of the ODEP-based approach for separating Raji cells from RBCs was experimentally investigated. The results showed that these two types of cells, with different concentration ratios, could be separated rapidly using externally-applied electrical field at a driven frequency of 50 kHz at 20 Vpp. In addition, we have found that in order to facilitate ODEP-based cell separation, Raji cells' adhesion to the OEK chip's substrate should be minimized. This paper also presents our experimental results of finding the appropriate bovine serum albumin concentration in an isotonic solution to reduce cell adhesion, while maintaining suitable medium conductivity for electrokinetics-based cell separation. In short, we have demonstrated that OEK technology could be a promising tool for efficient and effective purification of Raji cells from RBCs.
authors.affiliation: State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China; University of Chinese Academy of Sciences, Beijing, China; Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Liang
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Lianqing
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Yuechao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Zaili
authors.initials: Z
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China; Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Wen Jung
authors.initials: WJ
authors.lastname: Li
authors.affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Gwo-Bin
authors.initials: GB
authors.lastname: Lee
authors.affiliation: Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing, China.
authors.forename: Xiubin
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing, China.
authors.forename: Weijing
authors.initials: W
authors.lastname: Zhang
mesh_terms: D002051:Burkitt Lymphoma / Q000473:pathology*; D002448:Cell Adhesion; D002460:Cell Line; D002469:Cell Separation / Q000379:methods*; D004586:Electrophoresis / Q000295:instrumentation / Q000379:methods; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D018625:Microscopy, Atomic Force; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D012710:Serum Albumin, Bovine