GRAS Screens were developed by Hampton Research for the crystallization of proteins, including monoclonal antibodies. The screens utilize GRAS reagents that promote crystallization of biotherapeutics for bioprocess, bioformulation, and continuous flow manufacturing applications as well as crystallization of proteins for X-ray crystallography. Each of the chemicals in the GRAS Screens have been used under one or more of the following categories. As (1) a Generally Recognized As Safe (GRAS) substance, (2) a pharmaceutical excipient, (3) a normal physiological constituent, (4) a metabolic byproduct, and/or (5) a Everything Added to Food in the United States (EAFUS) substance. Formulation is based on a) data mining databases such as the Protein Data Bank (PDB), BMCD, and in house Hampton Research data, b) review and analysis of the patent and scientific literature, c) input from academic and pharma colleagues, and d) in house testing.

The primary crystallization reagents in GRAS Screen 1 and 2 are Polyethylene glycol 300, 400, MME 550, 600, 1,000, MME 2,000, 3,350 and 4,000 (high concentration) versus 24 unique secondary salts (low concentration), sampling pH 4 to 9 without an added buffer. The screens can be considered an extension to the PEG/Ion screens, albeit with a focus on GRAS reagents.

The primary crystallization reagent in GRAS Screen 3 and 4 are 24 unique salts (high concentration), versus Polyethylene glycol 300, 400, MME 550, 600, 1,000, MME 2,000, 3,350 and 4,000 as secondary reagents (low concentration), sampling pH 4 to 9 without an added buffer.

The primary crystallization reagents in GRAS Screen 5 and 6 are Polyethylene glycol 300, 400, MME 550, 600, 1,000, MME 2,000, 3,350 and 4,000, each sampled at 3 concentrations versus pH 4.5 to 10 sampling 8 unique buffers.

The primary crystallization reagents in GRAS Screen 7 and 8 are Ammonium - acetate, chloride, citrate, formate, phosphate, sulfate, tartrate, Potassium phosphate, Sodium acetate, Sodium - chloride, citrate, formate, phosphate, and tartrate, each sampled at 4 concentrations versus pH 4.5 to 10 sampling 8 unique buffers.

CAT NO NAME DESCRIPTION
HR2-451 GRAS Screen 1 1 mL, Deep Well block format
HR2-452 GRAS Screen 2 1 mL, Deep Well block format
HR2-453 GRAS Screen 3 1 mL, Deep Well block format
HR2-454 GRAS Screen 4 1 mL, Deep Well block format
HR2-455 GRAS Screen 5 1 mL, Deep Well block format
HR2-456 GRAS Screen 6 1 mL, Deep Well block format
HR2-457 GRAS Screen 7 1 mL, Deep Well block format
HR2-458 GRAS Screen 8 1 mL, Deep Well block format
HR2-459 GRAS Additive 1 mL, Deep Well block format