Nagler reaction is type of -

Its a neutralization test. Lecithinase test or Nagler's reaction is a biochemical test used to identify organisms which liberate phospholipases (lecithinases) e.g. Clostridium perfringens. The alpha (a) toxin of C. perfringens has phospholipase activity and hence, helps in differentiation of C. perfringens from other Clostridium spp that also produce lecithinase (C.baratti, C.absonum, C.bifermantans, C.sordelli and C.novyi) by neutralization of lecithin c activity by an antitoxin. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:112