Always check the manufacturer’s instructions for how to reconstitute your lyophilized proteins (ours is here) and the product datasheet, but here are some general useful tips:
Centrifuge before opening. During transportation the lyophilized protein can move around and may become lodged in the cap or on the sides of the vial. Before opening the lid, centrifuge to collect all the protein at the bottom of the vial.
Dissolve in the recommended solution. Many factors affect protein solubility including pH and ionic strength. Reconstitution in the recommended buffer will minimize loss of protein due to precipitation or adsorption onto plastic. For some proteins, e.g. TGF-β superfamily proteins, acid reconstitution is essential as the molecule is hydrophobic and insoluble at neutral pH. For these proteins it is also recommended to store the protein at low pH in order to maintaining the correct disulfide structure of the protein (the low pH minimizes disulfide bond exchange reactions).
Do not vortex! When reconstituting, do not vortex as the protein will not appreciate the shear stress or air. Simply let the sample sit for a few minutes with the solubilization buffer at room temperature and gently agitate or pipette up and down (avoid foaming).
Reconstituting within the recommended concentration range will benefit protein stability and aid maximum recovery. Keeping proteins at concentrations outside of this range may result in unstable protein conditions and activity decline. Attempting resuspension at a concentration above the recommended range may also exceed the maximum dissolved concentration of the protein, meaning some protein will not be dissolved.