Stain-free cell viability assay using lens-free shadow imaging technique (LSIT)

Abstract

Cell viability measurement is one of the crucial processes widely performed in various biological, environmental, pharmaceutical, and clinical cell researches. To measure the cell viability, over 100 years, the hemocytometer has been utilized by cell scientists. However, use of the hemacytometer holds some shortcomings such as operator’s subjective error or labor intensive process. To address this issue, recently, we have proposed a reagent-free and automated cell characterization method based on the Lens-free shadow imaging technique (LSIT)[1]. This lens-free shadow imaging technique has many advantages including high-throughput, low-cost, and compact size, over the traditional hemocytometer based cell viability measurement process. In this work we demonstrate a custom developed lens-free shadow imaging system enabling stain-free cell viability measurement for various cell lines such as BT474, L929, U87 and SWRC-G-R-O. We defined a shadow parameter, i.e., peak to peak distance (PPD), which corresponds to the degree of a cell’s viability without any staining procedures (see Fig. 1). Using this feature, we characterized the above mentioned cell lines for various concentrations by comparing viability results with standard hemocytometer and automated cell counter (Countess II, Invitrogen). The comparison between the manual hemocytometer and proposed stain-free method showed high correlation indices of 0.999, 0.999, 0.ed by cell scientists. However, use of the hemacytometer holds some shortcomings such as operator’s subjective error or labor intensive process. To address this issue, recently, we have proposed a reagent-free and automated cell characterization method based on the Lens-free shadow imaging technique (LSIT)[1]. This lens-free shadow imaging technique has many advantages including high-throughput, low-cost, and compact size, over the traditional hemocytometer based cell viability measurement process. In this work we demonstrate a custom developed lens-free shadow imaging system enabling stain-free cell viability measurement for various cell lines such as BT474, L929, U87 and SWRC-G-R-O. We defined a shadow parameter, i.e., peak to peak distance (PPD), which corresponds to the degree of a cell’s viability without any staining procedures (see Fig. 1). Using this feature, we characterized the above mentioned cell lines for various concentrations by comparing viability results with standard hemocytometer and automated cell counter (Countess II, Invitrogen). The comparison between the manual hemocytometer and proposed stain-free method showed high correlation indices of 0.999, 0.999, 0.