Fig. 7.

The quantified comparison between Holographic-LUCAS (λ = 500 nm) and a Hemacytometer for counting of RBCs as a function of the cell concentration is given in (a–b). For Holographic-LUCAS measurements, the RBC concentration for each sample is measured by automated processing of the acquired lensfree images, whereas for Hemacytometer measurements manual counting of several 10 × microscope images was used. The inserted figure in (a) zooms into the linear region (y = x) illustrating that Holographic-LUCAS can achieve a reliable performance for a cell density of up to ~3000 cells µL⁻¹. In (b) the minimum number of captured frames/images that is required for counting of ≥50 cells is shown for a Hemacytometer vs. Holographic-LUCAS. For a cell density range of <800 cells µL⁻¹, LUCAS always required the capture of a single frame, whereas a Hemacytometer, through a 10× microscope objective lens, required >10 different frames, corresponding to different field of views. (c–d) A zoomed field of view for automated characterization of an RBC solution is illustrated using Holographic LUCAS, where even partially overlapping cell signatures can be detected. The faint pattern in (c), which is not identified as an RBC is simply a dust particle at the surface of the sample.