Fig. 3.

Stimulus responsiveness and reversibility. a Brush height during a series of solvent swaps from 133 to 1.33 mM for a brush previously grown for 16 h. Scale bar, 10 µm. b Quantification of the brush height shows that at ultra-low ionic strengths, the brush stretches out by nearly 200%, peaking at 22.0 ± 2.5 µm (st. dev.) during the first exchange. While the brush swelling and shrinking is reversible, the repeated handling (and tension induced by stretching) leads to some loss of the HA, which is weakly bound to the HA synthase. As a consequence, a gradual decrease in the overall brush height is observed. Each gray data point corresponds to five independent measurements (211 × 211 µm² area) from one sample. Blue data points show the mean and st. dev.