Real-time fluorescence lifetime actuation for cell sorting using a CMOS SPAD silicon photomultiplier

Francescopaolo Mattioli Della Rocca, Jakub Nedbal, David Tyndall, Nikola Krstajic, David Day-Uei Li, Simon M. Ameer-Beg, Robert K. Henderson

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27 Citations (Scopus)
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Time-correlated single photon counting (TCSPC) is a fundamental fluorescence lifetime measurement technique offering high signal to noise ratio (SNR). However, its requirement for complex software algorithms for histogram processing restricts throughput in flow cytometers and prevents on-the-fly sorting of cells. We present a single-point digital Silicon Photomultiplier (SiPM) detector accomplishing real-time fluorescence lifetime-activated actuation targeting cell sorting applications in flow cytometry. The sensor also achieves burst-integrated fluorescence lifetime (BIFL) detection by TCSPC. The SiPM is a single-chip complementary metal oxide semiconductor (CMOS) sensor employing a 3232 single-photon avalanche diode (SPAD) array and 8 pairs of time-interleaved time to digital converters (TI-TDCs) with a 50 ps minimum timing resolution. The sensor’s pile-up resistant embedded centre of mass method (CMM) processor accomplishes lowlatency measurement and thresholding of fluorescence lifetime. A digital control signal is generated with a 16.6 s latency for cell sorter actuation allowing a maximum cell throughput of 60,000 cells per second and an error rate of 0.6%.
Original languageEnglish
Pages (from-to)673-676
Number of pages4
JournalOptics Letters
Issue number4
Publication statusPublished - 4 Feb 2016


  • fluorescence lifetime measurement
  • cell sorting
  • single photon avalanche diode

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