Posted on May 05, 2016, 6 a.m.
A novel acoustic tweezer device uses sound-based separation to identify circulating tumor cells.
With cancer, accurate detection and identification is key. In that existing methods of separation use tumor-specific antibodies to bind with the cancer cells and isolate them – requiring that the appropriate antibodies be known in advance, and other methods rely on specific molecular properties, Peng Li, from The Pennsylvania State University (Pennsylvania, USA), and colleagues have innovated a novel acoustic tweezer device about twice the size of a penny, with two sound transducers that separate cells by detecting the differential sizes and weights to push the circulating cancer cells out of the fluid stream and into a separate channel for collection. The power intensity and frequency used in this study are similar to those used in ultrasonic imaging, and each cell experiences the acoustic wave for only a fraction of a second. The researchers used two types of human cancer cells to optimize the acoustic separation -- HELA cells and MCF7 cells, which are similar in size. Their separation experiment yielded a separation rate of more than 83%. Writing that: “we report the development of an acoustic-based device that successfully demonstrates the isolation of rare [circulating tumor cells] from the clinical blood samples of cancer patients. Our work thus provides a unique means to obtain viable and undamaged [circulating tumor cells],” the study authors submit that: “The results presented here offer unique pathways for better cancer diagnosis, prognosis, therapy monitoring, and metastasis research.”
Peng Li, Zhangming Mao, Zhangli Peng, Lanlan Zhou, Yuchao Chen, Po-Hsun Huang, Cristina I. Truica, Joseph J. Drabick, Wafik S. El-Deiry, Ming Dao, Subra Suresh, Tony Jun Huang. “Acoustic separation of circulating tumor cells.” PNAS 2015 112 (16) 4970-4975.