OptiSol - Protein Solubility Screening Kit

This depends on the nature of the protein aggregate. The only way to find out is by experimental testing – and this is exactly what the OptiSol protein solubility screen does. Test 90 different mild formulations – different pH, salts, polymers, sugars, polyols, detergent, reducing agents. If the protein sample is reversibly aggregated, chances are the OptiSol screen will yield conditions that solubilize the sample. The formulations employed are rather mild. The goal is to solubilize the aggregate and yield functional protein. Will any aggregated protein samples get solubilized? No, some aggregates just contain ‘dead’ protein. You’ll need SDS or urea for such recalcitrant samples and obtain non-functional protein in return.

The protein concentration will be diluted by 11 times (15 µL/165 µL) in the reaction plate when the protein solution is combined with the formulations. Thus, one has to start with a stock protein solution that is 11 times the final solution concentration in the reaction plate. About 2 mL of protein stock solution is adequate. The required protein concentration depends on the extinction coefficient of the protein and the sensitivity of the protein detection assay. In our laboratory we developed a UV280 method using half-width UV 96-well plate and UV/vis plate reader. In our case, the UV280 absorbance in half-width UV280 wells has to be at least around 0.4 (absolute absorbance units).

All ingredients (buffers and additives) in an OptiPharma kit (except 3 control wells) are FDA approved pharmaceutical ingredients. If you have pharmaceutical proteins in any stages of pharmaceutical formulation development, OptiPharma is the one. OptiSol is applicable to various types of protein work (e.g. pharmaceutical, industrial, food, plant, crystallization work). Most additives in an OptiSol kit are not suitable for pharmaceutical formulations. For example, if you have a crude protein mixture that you want to solubilize, OptiSol is a good choice to start with.