Complement activity and conglutinin activity in stored bovine sera.

: Complement activity and conglutinin activity were measured in bovine sera stored under four conditions: phenolized (3 C), lyophilized (3 C), frozen (-23 C), and frozen (-57 C). The complement activity was lost after 12 weeks in phenol (3 C). The other three conditions, ranked in order of increasing effectiveness, are lyophilized (3 C) and frozen (-23 and -57 C). Conglutinin activity was lost after 23 weeks in phenol (3 C). The other three conditions, ranked in order of increasing effectiveness, are frozen (-23 C), lyophilized (3 C) and frozen (-57 C). Thus, the most effective condition to preserve complement and conglutinin simultaneously is freezing at -57 C.