Abstract
Many examples of anti-Rg (Rodgers) and anti-Ch (Chido) were studied by titration-inhibition to assess their ability to detect partial inhibition (p.i.). Generally, anti-Rg distinguishes the inhibition type Rg+ from Rg(+) (p.i.) and Rg-, whereas anti-Ch distinguishes Ch- from Ch+ and Ch(+) (p.i.). Serological procedures for the detection of p.i. in random samples and the results of typing 1 family, apparently giving anomalous results, are discussed.