1 .Sampling and sample preparationThis sample preparation method has been used with BAL volumes of 20mL to 200mL. Volumes of 200mLare more likely to provide sufficient cells although 50mLs are normally sufficient.Samples should be stored at room temperature or or 2-80C. They should not be frozen二BAL samples should be taken and stored in a siliconized glass containers or materials with a low protein binding factor so that the WBC are not adsorbed by the container walls.