Information on Master cell banks and Working cell banks?

[langsta at cc.umanitoba.ca]

I am new to the internet and I am searching for some information on Prep. and maintaining Master cell banks and working cell banks. 
I work at a Pharmaceutical R&D Lab. and would appreceite any information anyone could pass on. 

Thank you for any help

Please send any info direct to me at e-mail:

philip.squire at WPCUsrGrp.MB.CA