Researchers at the Singapore University of Technology and Design have developed a microfluidic device that can isolate cells from complex biological samples using sound waves. The technique could help doctors to accurately isolate specific types of cells from blood and other bodily fluids, which is useful for diagnostics and cell-based therapies.
Separating individual cells from complex biological samples, such as blood, is a challenge. The current gold-standard is a technique called fluorescence-activated cell sorting (FACS). However, the equipment for FACS is expensive, bulky, and difficult to use, requiring specially trained personnel.
An alternative approach lies in microfluidics. Researchers at the Singapore University of Technology and Design created a microfluidic device that can sort cells using a highly focused beam of sound. The system includes a disposable microfluidic channel, a fluorescence detection module, and a reusable sound wave generator.
To separate cells, the biological sample is mixed with a fluorescent labelling molecule, which will bind to markers that are specific to the cell type of interest. Then, the mixture is passed through the microfluidic channel, where a fluorescence detection module detects the labelled cells and activates a sound wave generator that gently deflects them into another channel for collection. The sound wave beam has a width of just 50 μm, and therefore allows for highly accurate sorting, down to the single cell level.
“Compared to conventional FACS systems, the merits of this cell sorting technology include a substantially simplified sorting mechanism that shrinks the instrument size, reduces its complexity and substantially lessens costs,” said Professor Dr. Ye Ai, a researcher involved in the study. “Not only that, but it also enables more accurate single cell level sorting and leaves no damage on target cells because sound waves are much gentler than electric fields widely used in conventional FACS systems.”