Separation and Isolation of Circulating Tumor Cells (CTC) from Whole Blood
Microfluidic acoustic cell separation and sorting (acoustophoresis) is a technique that utilizes ultrasonic standing waves to sort cells based on size and composition as they are passed through a microfluidic channel. A piezoelectric transducer is activated to set up a standing acoustic wave within the microfluidic device creating low pressure nodes through the separation channel. The acoustic forces from the wave focus particles above a desired size into the center of the channel, while smaller particles remain at the edges of the channel. By varying the voltage applied to the transducer, one can change the amplitude of the acoustic forces, resulting in a change in the size of particles focused to the center of the channel.
This technique is currently being applied toward the separation and sorting of circulating tumor cells (CTCs) from whole blood. CTCs vary in size but are generally larger than red blood cells (RBCs), which makes acoustophoresis a great candidate for label free separation and sorting. The force of the acoustic wave moves the larger cells, such as CTCs and white blood cells (WBCs), to the center of the separation channel while the RBCs and other small particles will remain at the outer edges of the channel. This will allow for the isolation and collection of CTCs from RBCs in a label free manner where they can then be collected and studied further.