Difco(tm) Shigella Antiserum Poly Group B, Catalog # 228351, in 3 mL vials individually sold or packed as a component in the Difco(tm) "Shigella Grouping Antiserum Set", Cat. 241108, Lot 6073806). Vials are labeled in part ***S. flexneri Serotypes 1-6***Becton, Dickinson and Company Sparks, MD 21152*** || Used for the identification of Shigella species by the slide agglutination test.