INTERIM REFERENCE PREPARATION OF LEUKEMIA INHIBITORY FACTOR (rDNA HUMAN)    

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AMPOULE CONTENTS
Each ampoule contains the residue after freeze drying of 1 ml of a solution containing: approximately 1 microgram leukemia inhibitory factor; 0.9% sodium chloride; 0.1% trehalose; 0.2% human serum albumin. The ampoules do not contain bacteriostat.

UNITAGE
The assigned potency is 10,000 arbitrary units per ampoule.

CAUTION
The preparation contains material of human origin which has been tested and found negative for HBsAg and HIV antibody. However, as with all materials of biological origin, this preparation should be regarded as potentially hazardous to health. It should be used and discarded according to your own laboratory's safety procedures. Such safety procedures probably will include the wearing of protective gloves and avoiding the generation of aerosols. Care should be exercised in opening ampoules or vials, to avoid cuts. This preparation is not for administration to humans.

USE OF AMPOULED MATERIAL
For all practical purposes, each ampoule contains the same quantity of the substances listed above. Dissolve the total contents of the ampoule in 0.5 ml of sterile distilled water. Rinse out the ampoule with a further 0.4 ml sterile distilled water and make up the total amount to 1 ml. The concentration is then at 10,000 units per ml. No attempt should be made to weigh out any portion of the freeze-dried material.

STORAGE
Unopened ampoules should be stored at -20oC. For economy of use, it is recommended that the solution be sub-divided into several small containers and stored at -40oC or below.

CITATION
In all publications in which this preparation is used as an assay calibrant, it is important that the title of the preparation and ampoule code be cited correctly.

This reagent is available in small amounts (approximately 1 microgram/sample) for use in the calibration of in vitro bioassays and in-house standards only and are not to be used for experimental purposes. Reference reagents are available to investigators with peer-reviewed support, at institutions or at commercial establishments and are limited to one sample of each reagent per year.