SCD consists of a two-step method for concentration, filtration and buffer exchange of Lipid Nanoparticles (LNP) to provide a homogeneous preparation suitable for injection.
They recovered 13 mg peptide/L culture, although they did use a rpHPLC step to perform buffer exchange of peptide samples for characterisation [20].
Ultrafiltration is a size-based membrane separation process that is used routinely for protein concentration and buffer exchange during the purification of biologics.
In brief, His-C2I was eluted with PBS containing 50 and 100 mM imidazole, fractions were pooled and buffer exchange and concentrating of protein was achieved with VivaSpin columns (Sartorius, Göttingen, Germany) according to the manufacturer's instructions.
The steps may include enzymatic reactions, tag hybridization, buffer exchange, and selective removal of cell debris and by-products of the reactions.
The buffer exchange of purified GST fusion proteins was carried out using PD10 gel filtration columns after concentrating the GST fusion protein to a reduced volume in 10 kDa cut-off Amicon Ultra centrifugal devices.
To remove the imidazole in the elution buffer, highly purified hBChE variant proteins were dialyzed with 2 L (one buffer exchange) of phosphate-buffered saline (PBS) [50 mM potassium phosphate (pH 7.5) and 150 mM NaCl].
After removal of free dye, and buffer exchange to 50 mM phosphate buffer pH 7.0, the efficiency of protein labeling was calculated as mole of dye per mole of protein according to manufacturer's protocols (Invitrogen).
