This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Quellung reaction is associated with - 
Select and explain. 
A. Capsular degeneration, B. Capsular delineation, C. Capsular absence, D. Lecithinase production
B: Capsular delineation
Answer: B: Capsular delineation 
Explanation: Ans. is 'b' i.e., Capsular delineation A suspension of pneumococci is mixed on a slide with a drop of the type specific antiserum and methylene blue. On the presence of homologous antiserum capsule becomes apparently swollen, sharply delineated and refractile.