Dynamic Coating with Hydroxypropyl Methylcellulose

In another system, the dynamic agent used for partial coating is hydroxypropyl methylcellulose (HPMC). In this approach, some interesting variants have been adopted. A new capillary is rinsed for 20 min with 1 M NaOH and then for 10 min with 0.1 M NaOH containing 0.3% HPMC. During this final washing, conditioning of the capillary and partial coating with HPMC occurs. This etching procedure (with 1 M NaOH), followed by a short renewal of the dynamic coating (0.3% HPMC in 0.1 M NaOH), is shown to provide data of the highest reproducibility. The sample proteins are dissolved in 2.5% Ampholine solution without adding HPMC. The anolyte is the standard ten mM phosphoric acid solution, whereas the catholyte consists of 20 mM NaOH in the presence of 0.1% HPMC. The sample is introduced as a plug, occupying only 10–50% of the capillary length at the anodic side, the remaining being filled with catholyte. Since the entire stack of proteins will eventually be displaced towards the cathode by the EOF, this initial sample plug distribution allows more time to reach a good focusing pattern before sample passage in front of the detector. If you are looking for high quality, high purity, and cost-effective Hydroxypropyl methylcellulose, or if you require the latest price of Hydroxypropyl methylcellulose, please feel free to email contact mis-asia.