A Study of Intracellular Ice Formation in Jurkat Cells

The objective of this study was to characterize the IIF behavior of Jurkat cells in isotonic conditions in the absence of any cryoprotective agents. The Jurkat cells were collected from culture and then washed and re-suspended in Dulbecco’s Phosphate Buffered Saline (PBS). The freezing experiments were carried out at defined freezing protocols and at various freezing rates of 5, 20, 30 and 50 °C/min. The results suggest there was no substantial evidence of intracellular ice formation at lower cooling rates of 5, 20 and 30° C/min. The first conspicuous indication of intracellular ice formation (IIF) was observed at a freezing rate of 50 °C/min. At this cooling rate, unlike the usual sudden blackening of cells, the cells suddenly grew and exploded suggesting the formation of intracellular ice, which was reminiscent of a prior observed phenomenon for IIF.