Each of the chemicals in GRAS Screen 5 and 6 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.

GRAS Screen 5 samples four low molecular weight Polyethylene glycols (300, 400, MME 550, and 600) at three concentrations versus eight unique buffers encompassing pH 4.5 to 10. GRAS Screen 5 is supplied in a 96 Deep Well block format and is compatible with robotic and multi-channel pipet liquid handling systems. GRAS Screen 5 is compatible with vapor diffusion, free interface diffusion, and microbatch crystallization methods. For research use only.

GRAS Screen 6 samples four medium molecular weight Polyethylene glycols (1,000, MME 2,000, 3,350, & 4,000) at three concentrations versus eight unique buffers encompassing pH 4.5 to 10. GRAS Screen 6 is supplied in a 96 Deep Well block format and is compatible with robotic and multi-channel pipet liquid handling systems. GRAS Screen 6 is compatible with vapor diffusion, free interface diffusion, and microbatch crystallization methods. For research use only.