Automated Microfiltration to Purify GFP-His from E.coli

摘要

Microfiltration is ideally suited to the separation of cultured cells from growth medium,as well as contaminant and particle removal in biopharmaceutical processes.When using hollow fibers,the cross flow rate is converted into a shear rate,which is a function of flow rate per fiber and the fiber inner radius.Since the fibers are relatively open they rely on a high cross flow rate to create enough turbulent flow to prevent the cells from accumulating at the membrane surface.The cross flow rate,or shear rate,and the amount of restriction on the permeate flow are crucial parameters to processing such high density cell suspensions without immediate membrane fouling and clogging of the filter.Here we outline steps for optimizing the puriflcation of Green Fluorescent Protein-His from an E.coli cell homogenate,a challenging procedure involving a great concentration of protein,DNA,and a broad range of fragment sizes.