The Microflow Cytometer

Integrated optical detection in a microfluidic platform recently got an immense attention, on such integrated platforms light and fluids are engineered synergistically to implement highly sensitive and portable lab-on-chip biochemical sensors. Integrated optofluidic platforms were successfully demonstrated in last few years for various applications such as controlling liquid motion using light, sunlight-based fuel-production, and flow cytometry. Various microflow analyzers were developed for different applications including counting and studying biological cells, bacteria, molecular biology, and cellular DNA. Microflow cytometer is an instrument, which interrogates a small volume of fluid to detect and sort biological cells/samples present in a sample fluid. Presently, the flow cytometry is the state of the art for biological sample analysis due to its capability for detailed analysis. However, conventional flow cytometers are very expensive and thus are available only in centralized research facilities and major health care centers. Similarly, due to its complexity, regular maintenance and skilled expertise are required to operate the machine, analyze data, and make reports. In the last few years, several research works have been carried out to design cost-effective and portable microflow cytometer by employing the advancements in the field of microfluidic and microfabrication technology. However, the complicated techniques required for three-dimensional focusing of biological cells flowing inside the microchannel and controlling inter distance between them in the optical window are the primary hindrances in the development of a microflow cytometer. Another challenge in the development of microflow cytometer is the isolation of target cells downstream after detection. In literature, various techniques have been reported to achieve the sorting of target cells. Therefore, development of microflow cytometers is mainly concentrated on focusing of samples in a microchannel, miniaturization of optical and supporting flow systems, integration of electronics on the same chip, and development of optimal sorting technique. Hence, by incorporating above mentioned developments, microflow cytometer can be used successfully to focus, detect, and sort the particles with a high throughput which can lead to a proper analysis of biological samples.