Reaction catalyzed by N-acetyllactosamine synthase (2.4.1.90)

		+			=			+
	UDP-alpha-D-galactose	+		4-methylumbelliferyl beta-D-glucopyranoside	=		UDP	+		4-methylumbelliferyl 4-O-beta-D-galactopyranosyl-beta-D-glucopyranoside