Figure 6.

Long-term reusability and storage stability of enzymes immobilized via distinct adapters. Enzymatic activities were monitored through a period of 3 weeks for the different layouts described for Figure 5. Sample wells were either subjected to 14 consecutive uses (A) to determine the residual activities under these conditions, or prepared in parallel and stored idle up to the testing time point, as indicated (B). (A) Immobilized enzymes were tested for their reusability and concomitant storage stability over 3 weeks, using 1.5 μg (non-saturated conditions) and 5.5 μg adapters (saturated conditions), or the corresponding linker molarity, according to the legend. Values determined for bare plates ranged below the level of detection from the second measurement on, and are not added to the diagram (n.a.). After the initial catalytic activities were determined, wells were washed with 1x PBS-T, stored in 10 mM SPP pH 7.0 at 4°C for at least 24 h, and incubated with substrate solution, washed and stored repeatedly, as indicated by the data points and legend. Arrows indicate half-lives of the distinct enzyme-adapter systems, corresponding to 50% of their referential initial activity. (B) Activity of enzymes exposed on different adapters as above, subjected to a first use at the different time points indicated, over a period of 3 weeks. For details, refer to text.