Figure 2.

Analysis of protein stability after passing robotic systems washed with different cleaning solutions. (a) Samples from stock solutions of a purified protein (−), the same solution after incubation at room temperature (RT) or aspiration through the nano-needle (NN passage) or aspirated through the nano-needle after application of an extended wash protocol including 1 mM NaOH rinses (NN passage ext. wash) were analyzed by SDS–PAGE (15% acrylamide). Bands were visualized by Coomassie staining. (b) The same protein sample as in (a) after incubation at room temperature (RT) or aspirated through the nano-needle washed with SDS following Zymit cleaning (NN passage SDS wash) were analyzed as in (a). Neither the extended wash nor the SDS treatment could efficiently block protein degradation. In each case, lane M contains molecular-weight markers (labelled in kDa).