Node-pore sensing: A label-free platform to screen single cells for their phenotypic profile
Flow cytometry is one of the cornerstones of biomedical research and clinical diagnostics. With its ability to screen individual cells for multiple protein epitopes simultaneously and subsequently identify sub-populations of cells, flow cytometry has had a profound impact in a broad range of areas including immunology, cancer, and regenerative medicine. While the current state of-the-art is 18 parameters, flow cytometry is often “practically” limited to 6-10 parameters, as emission spectral overlap is of concern and highly complex analysis to decouple such overlap is needed. We have developed a rapid, label-free method of screening cells for their phenotypic profile, which we call Node-Pore Sensing (NPS). NPS involves measures the modulated current pulse caused by a cell transiting a microchannel that has been segmented by a series of inserted nodes. When the segments between the nodes are functionalized with different antibodies corresponding to distinct cell-surface antigens, cells whose antigens interact specifically with the functionalized antibodies in a particular segment will travel more slowly through that section of the channel than that through the isotype-control. Surface-marker identification is accomplished by comparing transit times within the modulated pulse. I will show the versatility of NPS and discuss how we are using this method in a pilot clinical study to phenotype acute myeloid leukemia patient samples. Furthermore, I will discuss the next-generation NPS, which involves using analysis techniques borrowed from radar and telecommunications theory.