Fig. 2. Hyaluronan production in Has2-transfected cells. (A) Nearly confluent cultures were stained for cell-associated hyaluronan using the bHABC probe. Wt, wildtype; M2, mock; A22, antisense; S29, sense cell line. Note the elongation of some of the most intensely stained cells in the S29 sense line (arrows). (B) Optical densities of the DAB signal, representing cell-associated hyaluronan, were assayed in cultures of equal density to those in (A) using microscopic image analysis. The bars show the s.e. of 10 randomly taken microscopic fields. (C) Hyaluronan secreted into the growth medium by the sense (S25-S30), antisense (A9-A25) and mock-transfected (M2) cells was determined as fluorophore-tagged, enzymatically liberated disaccharides and plotted as a function of cell density. Linear regression lines for the antisense and sense cell lines are shown.