A new method for permeabilization of the plasma membrane of cultured mammalian cells. III. Internalization of fluorescent dextrans into cultured mammalian cells by vortex-stirring in the presence of high molecular weight polyacrylic acid.

Using a new technique of vortex-stirring of cells with high molecular weight polyacrylic acid (A-119), non-permeant fluorescein isothiocyanate-labeled dextrans (FDs) of various molecular weights were tested to determine the degree of their internalization into cultured murine leukemia L1210 cells. Flow cytometric analyses of the treated cells revealed that FD4 with a molecular weight (MW) of 4400 was incorporated in an amount 13.2 times greater than that of the control and that FDs with MW of 19000 and 38260 were incorporated at levels several times greater than control levels, by vortex-stirring cells with A-119 for 10 s followed by maintenance at 0 degree C for 10 min. Results of the present study indicate that this permeabilization procedure might be useful to introduce poorly permeable materials into cultured mammalian cells, which would be beneficial in various fields of biological research.