Flow cytometry is a useful tool that employed in diagnoses of various blood diseases, basic research, clinical trials or even as a “cell sorter” instrument. Currently, flow cytometry involves an elaborate arrangement of mirrors and filters to split the signals from the device into the different wavelengths. This setup often requires several lasers and multiple detection channels as well as skilled operators for the complex system.
Researchers at the University of Alberta have developed a new flow cytometry device based on a single fixed detector (e.g. a PMT) and a grating-based spectrometer lab-on-a-chip device. The method is based on the wavelength dependent quantity of the separation between the diffracted orders of the grating. By knowing the value of the spacing, the wavelength of a fluorescent particle can be determined from the linear wavelength-grating relationship. Conversely, if the wavelength of the particle is known, the particle’s velocity can be calculated by obtaining the corresponding particle spacing and using the elapsed time between the two orders from the PMT reading.