{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:52:51Z","timestamp":1760241171621,"version":"build-2065373602"},"reference-count":19,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,12,18]],"date-time":"2019-12-18T00:00:00Z","timestamp":1576627200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013380","name":"Global Water Futures","doi-asserted-by":"publisher","award":["20009406"],"award-info":[{"award-number":["20009406"]}],"id":[{"id":"10.13039\/501100013380","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Gating or threshold selection is very important in analyzing data from a microflow cytometer, which is especially critical in analyzing weak signals from particles\/cells with small sizes. It has been reported that using the amplitude gating alone may result in false positive events in analyzing data with a poor signal-to-noise ratio. Transit time (\u03c4) can be set as a gating threshold along with side-scattered light or fluorescent light signals in the detection of particles\/cells using a microflow cytometer. In this study, transit time of microspheres was studied systematically when the microspheres passed through a laser beam in a microflow cytometer and side-scattered light was detected. A clear linear relationship between the inverse of the average transit time and total flow rate was found. Transit time was used as another gate (other than the amplitude of side-scattering signals) to distinguish real scattering signals from noise. It was shown that the relative difference of the measured microsphere concentration can be reduced significantly from the range of 3.43%\u20138.77% to the range of 8.42%\u2013111.76% by employing both amplitude and transit time as gates in analysis of collected scattering data. By using optimized transit time and amplitude gate thresholds, a good correlation with the traditional hemocytometer-based particle counting was achieved (R2 &gt; 0.94). The obtained results suggest that the transit time could be used as another gate together with the amplitude gate to improve measurement accuracy of particle\/cell concentration for microfluidic devices.<\/jats:p>","DOI":"10.3390\/s20010014","type":"journal-article","created":{"date-parts":[[2019,12,23]],"date-time":"2019-12-23T03:15:01Z","timestamp":1577070901000},"page":"14","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Systematic Study on Transit Time and Its Impact on Accuracy of Concentration Measured by Microfluidic Devices"],"prefix":"10.3390","volume":"20","author":[{"given":"Yushan","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tianyi","family":"Guo","sequence":"additional","affiliation":[{"name":"Forsee Instruments Ltd., Hamilton, ON L8P 0A1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Changqing","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Engineering Physics, McMaster University, Hamilton, ON L8S 4L7, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3174","DOI":"10.1039\/c1lc20473d","article-title":"Classification of cell types using a microfluidic device for mechanical and electrical measurement on single cells","volume":"11","author":"Chen","year":"2011","journal-title":"Lab Chip"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1007\/s10544-008-9262-8","article-title":"Deformability study of breast cancer cells using microfluidics","volume":"11","author":"Hou","year":"2009","journal-title":"Biomed. 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