Salt-stress induced cell death in the unicellular green algae Chlorella vulgaris was investigated by incubating the algae cells with high salinity NaCl solution (150 mM) which typically causes cell damage or cell-death due to the osmotic potential which affects the permeability of the plasmalemma, cell growth and metabolic rate of the algae cells. The damaged cells can be characterized by the presence of non-uniform cell membrane while dead cells appear transparent due to leakage of chloroplast (without staining; encircled red ) or brown in color (after iodine staining; encircled yellow) as shown in the images captured using Foldscope. In contrast, the live cells appear green (or dark green in case of iodine staining) in color.