title: Capsular serotyping of Streptococcus pneumoniae using the Quellung reaction.
abstract: There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal epidemiology, capsular serotyping can provide useful information for vaccine efficacy and impact studies. The Quellung reaction is the gold standard method for pneumococcal capsular serotyping. The method involves testing a pneumococcal cell suspension with pooled and specific antisera directed against the capsular polysaccharide. The antigen-antibody reactions are observed microscopically. The protocol has three main steps: 1) preparation of a bacterial cell suspension, 2) mixing of cells and antisera on a glass slide, and 3) reading the Quellung reaction using a microscope. The Quellung reaction is reasonably simple to perform and can be applied wherever a suitable microscope and antisera are available.
authors.affiliation: Pneumococcal Research, Murdoch Childrens Research Institute.
authors.forename: Maha
authors.initials: M
authors.lastname: Habib
authors.affiliation: Pneumococcal Research, Murdoch Childrens Research Institute.
authors.forename: Barbara D
authors.initials: BD
authors.lastname: Porter
authors.affiliation: Pneumococcal Research, Murdoch Childrens Research Institute; Department of Microbiology & Immunology, The University of Melbourne; catherine.satzke@mcri.edu.au.
authors.forename: Catherine
authors.initials: C
authors.lastname: Satzke
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000737:chemistry / Q000276:immunology; D000918:Antibody Specificity; D016667:Bacterial Capsules / Q000145:classification* / Q000276:immunology; D006736:Horses; D007106:Immune Sera / Q000737:chemistry / Q000276:immunology; D012703:Serotyping / Q000379:methods*; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007106:Immune Sera