INTERIM REFERENCE PREPARATION OF TUMOR NECROSIS FACTOR b/LYMPHOTOXIN recDNA HUMAN)    

87/640

AMPOULE CONTENTS
Highly purified human tumor necrosis factor beta (recDNA) derived from E. coli containing the tumor necrosis factor protein beta coding DNA sequence, supplied by Boehringer-Ingelheim, Vienna, Austria, was diluted in phosphate buffered sale (PBS) containing human serum albumin (HSA; 6 mg/ml) of a final tumor necrosis factor beta concentration of 1 microgram/ml. This tumor necrosis factor beta containing solution was filtered, divided into 1 ml amounts in glass ampoules and freeze-dried under stringent conditions. The reconstituted tumor necrosis factor beta solution has a potency of approximately 150,000 units/ml by using L-cell cytotoxicity assays in the presence of actinomycin D (1 microgram/ml) and read at 24 hour incubation. These units are not equivalent to those assigned to tumor necrosis factor alpha (87/650).

UNITAGE
The assigned potency is approximately 150,000 units/ml.

CAUTION
The freeze-dried preparation has been tested and found negative for HBsAg and anti-HIV. However, as with all preparations of human origin, this material cannot be assumed to be free from infectious agents. Suitable precautions should be taken in the use and disposal of the ampoule and its contents.

USE OF AMPOULED MATERIAL
It is proposed that this preparation will serve as an interim reference preparation for human tumor necrosis factor beta by using the potency value of 150,000 units/ml for calibration of cytotoxicity assays. These units are not equivalent to those assigned to tumor necrosis factor alpha (87/650).