GRAS Screen™ 7 and 8 were developed by Hampton Research for the crystallization of proteins, including monoclonal antibodies.
Each of the chemicals in GRAS Screen 7 and 8 has 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 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.
GRAS Screen 7 samples 9 salts (Ammonium-acetate, chloride, citrate, formate, phosphate, sulfate, tartrate, Potassium phosphate, & Sodium acetate) at 4 concentrations, sampling 8 unique buffers (pH 4.5 to 10.0) as well as 8 buffer controls without salt. GRAS Screen 7 is supplied in a 96 Deep Well block format and is compatible with robotic and multi-channel pipet liquid handling systems. GRAS Screen 7 is compatible with vapor diffusion, free interface diffusion, and microbatch crystallization methods. For research use only.
GRAS Screen 8 samples 5 salts (Sodium - chloride, citrate, formate, phosphate & tartrate) at 4 concentrations, sampling 8 unique buffers (pH 4.5 to 10.0). GRAS Screen 8 is supplied in a 96 Deep Well block format and is compatible with robotic and multi-channel pipet liquid handling systems. GRAS Screen 8 is compatible with vapor diffusion, free interface diffusion, and microbatch crystallization methods. For research use only.
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