Enhanced luminescent or luminometric assay

Claim 1

In a luminescent or luminometric assay which comprises carrying out a chemiluminescent reaction between a peroxidase enzyme, an oxidant, and a chemiluminescent 2,3-dihydro-1,4-phthalazinedione and measuring or detecting the chemiluminescence thereby produced, the improvement wherein the reaction is carried out in the presence of a phenolic compound of the formula: ##STR3## wherein: (i) A and B are hydrogen; and R is halogen; phenyl; ##STR4## being --CH 2 --, --O-- or --N═N-- and V being hydrogen or Y being --O--, --S-- or --S--S-- and V being hydroxy; ##STR5## W being hydrogen or carboxy; ##STR6## --CH═CH--Z, Z being carboxy or 2,4-dinitrophenyl; --CH 2 CH 2 COOC 2 H 5 ; or C 1 -C 6 alkyl; (ii) A is hydrogen; B is halogen or C 1-6 alkyl; and R is halogen; (iii) A is halogen; B is hydrogen; and R is halogen or phenyl; or (iv) A is hydrogen or halogen; R and B together represent a naphthalene nucleus-completing chain which, read in the direction from R to B, is of formula ##STR7## X being hydrogen or halogen, whereby the compound of formula (1) is a beta-naphthol of formula: ##STR8## and "halogen" in every occurrence in (i) through (iv) above means chlorine, bromine or iodine.