The overarching goal of this project is to develop Node-Pore Sensing (NPS), an innovative label-free microfluidic technique, such that it could go beyond flow cytometry in terms of number of markers that can be practically and routinely screened simultaneously and in a non-destructive manner. Currently, flow cytometry is practically limited to 6-10 markers due to spectral emission overlap of the different fluorochromes used simultaneously. NPS measures the transit time of a cell as it interacts (specifically or non-specifically) with antibodies functionalized in a microfluidic channel that has been segmented by nodes. Specific interactions between cell-surface receptors and the functionalized antibody retard the cell, leading to longer transit times and subsequent determination of a particular surface-marker presence. This high-risk, high-reward R21 project has two Specific Aims: ? Aim 1: To optimize device coding and processing for high throughput screening and real-time analysis. We will design and develop a unique NPS platform based on Barker codes that enable high- resolution detection even with low signal-to-noise ratios (SNRs). Barker codes are binary signals that are often used in radar and telecommunications to which NPS is analogous. ? Aim 2: To incorporate sorting technology onto the NPS platform developed in Aim 1. We intend to realize the full potential of NPS and integrate a sorting technology to the NPS platform. The sorting technology will be based on mechanical pressure actuation to sort cells rapidly into phenotypic sub- populations for downstream analysis and/or culture. NPS development and proof-of-principle will be based on screening and sorting breast-cancer cell lines, MCF10A, MCF-7, MDA-MB-436, and MDA-MB-231-all of which have different malignancy and metastatic status-for markers EpCAM, CD44, CD24, CD29, CD49f, CD133, Axl, MUC1, EGFR, and ErbB2. By focusing on these markers, we would have an immediate impact in studies involving characterizing sub-populations of circulating tumor cells from patients with metastatic breast cancer. Thus, our proof-of-principle for a fully developed NPS has high impact. The proposed integrated multi-marker NPS and sorting technology proposed has potential for transformative impact in a number of fields ranging from fundamental life sciences research to point-of-care diagnostics. For example, flow cytometry is the cornerstone to diagnosis for many of the hematologic malignancies. With our screening/sorting technique, we could detect minimal residual disease and remission states. Beyond clinical diagnosis, our technology could be employed to characterize, for instance, changes in surface-marker expression during stem-cell differentiation in order to identify and isolate potentially important and rare sub-populations.

Public Health Relevance

While a cornerstone to both biomedical research and clinical diagnosis, flow cytometry is often limited to screening 6-10 markers because of spectral emission overlap. We will develop Node-Pore Sensing (NPS), a label-free, microfluidic-based method that could ultimately screen, directly and without loss of sensitivity, N > 10 cell-surface markers simultaneously, and subsequently sort cells into phenotypic sub-populations. We will demonstrate NPS's powerful capabilities by screening and sorting into sub-populations breast- cancer cell lines that have different malignancy and metastatic status for specific markers that indicate metastatic potential.

National Institute of Health (NIH)
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Exploratory/Developmental Grants (R21)
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Instrumentation and Systems Development Study Section (ISD)
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Lash, Tiffani Bailey
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University of California Berkeley
Engineering (All Types)
Biomed Engr/Col Engr/Engr Sta
United States
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Kellman, Michael; Rivest, Francois; Pechacek, Alina et al. (2018) Node-Pore Coded Coincidence Correction: Coulter Counters, Code Design, and Sparse Deconvolution. IEEE Sens J 18:3068-3079
Kellman, Michael; Rivest, Francois; Pechacek, Alina et al. (2017) BARKER-CODED NODE-PORE RESISTIVE PULSE SENSING WITH BUILT-IN COINCIDENCE CORRECTION. Proc IEEE Int Conf Acoust Speech Signal Process 2017:1053-1057