Cell Proliferation Study of Human Osteosarcoma Cell Line (U2OS) using Alamar Blue Assayand Live Cell Imaging

Abstract

Cell proliferation can be described as the process in which cells reproduce themselves by growing and then dividing into two equal copies. The cancer cell differs from the normal cell in a sense that it is aberrantly regulated. Failure to regulate functions of biomolecules that are necessary for survival, proliferation, differentiation as well as expression of many cell-type functions leads to an altered phenotype and cancer. The aim of the study is to assess the proliferation of human osteosarcoma cell line (U2OS) using Alamar Blue and live cell imaging.Standard curve for U2OS cells was produced by incubating different counts of U2OS cells for 24 hours before addition of Alamar Blue dye and absorbance reading at 570 nm and 600 nm. For cell proliferation study, 1 x 10 3 of U2OS cells were cultured for 10 days. Absorbance readings were recorded once in every two days (day 2, 4, 6, 8, 10) and the percentage of Alamar Blue reduction was calculated. The cell division process was studied using live cell imaging for 48 hours employing fluorescent expression systems. From both Alamar Blue assay and live cell imaging, population doubling time (PDT) was determined. The percentage of Alamar Blue reduction increased from day 2 to 10 which indicated the increase in the number and proliferation activity of U2OS cells. The PDT of U2OS cells determined based on Alamar Blue assay was 29.15 hours and through live cell imaging, was 32 ± 3 hours.U2OS cells proliferate over days based on Alamar Blue assay and live cell imaging with PDT of approximately 29 hours.