title: Determination of Protein Content in Alhydrogel®-Based Vaccines by O-Phthalaldehyde Assay.
abstract: The quantification of antigens adsorbed to aluminum-based adjuvants (alum) typically involves a method that first extracts antigen from the alum followed by the quantification of the antigen available in the extract. Extraction procedures often result in less than 100 % desorption of the antigen from the alum adjuvant and may alter the conformation of the antigen, reducing the accuracy of the subsequent method used for quantification. There is no generic method available for directly assessing the protein content when formulated on alum. Here we offer a method that can directly quantify protein adsorbed to Alhydrogel®using a simple fluorescence assay that is highly accurate and reproducible for Alhydrogel®formulations containing 25-400 μg/mL of antigen.
authors.affiliation: Laboratory of Malaria Immunology and Vaccinology, National Institutes of Allergy and Infectious Disease, National Institutes of Health, 5640 Fishers Lane, Rockville, MD, 20852, USA. krausch@niaid.nih.gov.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Rausch
authors.affiliation: Laboratory of Malaria Immunology and Vaccinology, National Institutes of Allergy and Infectious Disease, National Institutes of Health, 5640 Fishers Lane, Rockville, MD, 20852, USA. dzhu@niaid.nih.gov.
authors.forename: Daming
authors.initials: D
authors.lastname: Zhu
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry*; D000536:Aluminum Hydroxide / Q000737:chemistry*; D000941:Antigens / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D014612:Vaccines / Q000032:analysis*; D009764:o-Phthalaldehyde / Q000737:chemistry*
chemical_list: D000276:Adjuvants, Immunologic; D000941:Antigens; D011506:Proteins; D014612:Vaccines; D000536:Aluminum Hydroxide; D009764:o-Phthalaldehyde
keywords: Alhydrogel; Alum; Aluminum hydroxide; OPA; Protein assay; Protein quantification; Vaccine; o-phthalaldehyde