MALDI-TOF-MS Kinetic Analysis on Chip

Combination and mixing of droplets at well-defined time intervals was accomplished using a custom-built relay board interfaced with a laptop PC controlled using Matlab. Each 0.5 pL droplet was initially manually loaded across one of the outermost electrode gaps, and then brought into the center for rapid mixing. 

Details of the model PTPase reaction are available elsewhere.12,15 However, in brief, the following equations were used to deduce the rate constants k and k2  

Nonlinear regression using Matlab was used to fit Equation (12.3) to Km values obtained from the literature,15 experimentally relevant concentrations and scaled [EP]/[E]0 data calculated as the area under EP divided by the sum of the EP and E areas. 

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