EasyCal Vial calibration standards are ready to use and do not require any special preparation – simply add solvent to the 2 mL vial. These standards consist of the most widely-used polystyrene and polyethylene oxide standards for GPC-SEC calibration. The polymers are specially prepared to ensure an extremely narrow molecular weight distribution, providing accurate GPC-SEC calibration. In addition, the polymer molecular weights are extremely well characterized using multiple characterization techniques.