Application of binary buffer systems to free flow cell electrophoresis

The applicability of free flow electrophoresis (FFE) was expanded towards p rocessing of sensitive cells. The chamber medium was adjusted to a physiolo gic pH of 7.35 by a mixture of N-(2-hydroxyethyl)piperazine-N'-(3-propanesu lfonic acid) (EPPS) and 2,2-bis(hydroxymethyl)-2,2'2"-nitrilotriethanol (BI STRIS). These substances proved to be nontoxic to sensitive cells such as h uman smooth muscle or thyroid cells. They enhanced the electrical conductiv ity of the medium only slightly so that a new cell electrophoresis separati on medium could be prepared, which contained 30 mM NaCl together with or wi thout 1 mM CaCl2 but did not generate problems of overheating the fluid. Su spended in this medium, human smooth muscle cells as well as human thyroid carcinoma cells remained viable single cells for at least 120 min. After th is period they could be recultured to form monolayers. if electrophoresed i n the Octopus preparative FFE device, they migrated as single cells and did not clot; therefore, their electrophoretic behavior could be determined ex actly.