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Quellung Reaction: Introduction, Principle, Procedure, Result Interpretation, Uses and Keynotes
Introduction of Quellung Reaction The quellung reaction is the swelling of the capsule and it is also called or Neufeld reaction which is the gold standard technique for serotyping pneumococcus and this quellung reaction was first described in 1902 by the scientist Fred Neufeld who applied this test only to Streptococcus pneumoniae. Capsular serotyping of the individual strains of S. pneumoniae is performed by the microscopic “precipitin test. This reaction is also applicable in the bacterial...
Ascospore Agar: Introduction, Principle, Procedure, Colony Morphology, Uses and Keynotes
Introduction of Ascospore Agar Ascospore Agar is recommended medium for the expression of ascospores and therefore it is useful for enrichment and detection of ascosporogenous yeasts. It is the modification of the McClary medium with the addition of potassium acetate in place of sodium acetate. Saccharomyces cerevisiae is the most common yeast used to show expression ascopores. Principle of Ascospore Agar Yeast extract and dextrose supply the nutrients required for the growth and also stimulate ascospore formation...
L-pyrrolidinyl-β-naphthylamide Test: Introduction, Principle, Procedure, Result Interpretation, Uses and Keynotes
Uses of L-pyrrolidinyl-β-naphthylamide Test L-pyrrolidinyl-β-naphthylamide Test short form is PYR test. This PYR test uses to identify the capability of organisms utilizing substrate, PYR by L-pyrroglutamyl amino-peptidase. Application of this test are as follows: Identification of Streptococcus pyogenes (PYR positive)from other beta-hemolytic Streptococci (Negative) Differentiation of Enterococcus species (PYR positive) from group D Streptococci (Streptococcus bovis, Streptococcus equinus) which are PYR negative. It is used in the identification of Escherichia coli (PYR Negative), separating it from other indoles positive, lactose positive,...