Figure 2
From: Fluorescence lifetime imaging with a megapixel SPAD camera and neural network lifetime estimation
Wide-field fluorescence lifetime measurements of Convallaria and HT1080 cells. First column: least-squares (LSQ) deconvolution; second column: ANN deconvolution; third column: temporal sum of pile-up and background corrected intensity data clipped to selected intensity values to reveal dimmer structures. (a)–(c): high photon count measurements of Convallaria (100 s acquisition). Mean lifetime measurements for LSQ (processing time, 56 min) and ANN deconvolution (processing time, 2.7 s) yield similar values. Spatial sampling is 0.47 \(\upmu\)m/pixel with a 7% active area fill-factor. (d)–(f) Low photon counts measurements of Convallaria at a total acquisition time of 1 s. LSQ (processing time, 58 min) and ANN (processing time 2.7 s) deconvolution results are similar. Spatial sampling is 0.47 \(\upmu\)m/pixel. (g)–(i) measurements of HT1080 (fibrosarcoma) cells expressing Clover41. As with previous data-sets with LSQ (processing time, 23.2 min) and ANN (processing time, 3.6 s) retrievals. Spatial sampling is 0.33 \(\upmu\)m/pixel. We found the HT1080 cells to be dimmer than the Convallaria cells. HT1080 cells yield around 100 photons per second on average in the brightest region, compared to around 2500 in the brightest region of Convallaria. Scale bars 50 \(\upmu\)m.
