Stability of antigen E in commercially prepared ragweed pollen extracts.
Aqueous ragweed pollen extracts (20,000 PNU/ml or 78,000 PNU/ml) lose 50% of their Antigen E content within 5 months of storage at 4 degrees C. Glycerinated extracts and lyophilized ragweed pollen extracts retain their Antigen E content for over 15 months with little or no loss. The preservative phenol in aqueous extracts is destructive to Antigen E probably by protein denaturation. The stability of ragweed extracts as measured by Antigen E content is markedly enhanced with little loss after 15 month storage at 4 degrees C, when the extract is prepared as an alum precipitated suspension.
D000535:Aluminum; D000941:Antigens; D001681:Biological Assay; D002021:Buffers; D004355:Drug Stability; D005069:Evaluation Studies as Topic; D005612:Freeze Drying; D005990:Glycerol; D006207:Half-Life; D008722:Methods; D010944:Plants / Q000276:immunology*; D011058:Pollen; D012882:Skin Tests; D013696:Temperature; D013997:Time Factors
D000941:Antigens; D002021:Buffers; D000535:Aluminum; D005990:Glycerol