How Long Does Standardized Redtop Grass Last?

STORAGE AND HANDLING The expiration date of standardized grass pollen extract is listed on the container label. The extract should be stored at 2 - 8°C, if possible, and kept in this temperature range during office use. Dilutions of the stock concentrate containing less than 50% glycerol are less stable. If loss of potency is suspected, such dilutions should be checked by skin testing with equal units of a freshly prepared dilution.