Back-ground Determination for Thyroid Bioassay

[farhad@ucla.edu (farhad semnani)]

Dear Rad Safers who perform Thyroid Bioassays:

A co-worker of mine is curious to know that how back-ground is determined
for thyroid monitoring.  Would "Control Background" which is obtained from a
number of un-exposed and healthy thyroid glands be appropriate, or do you
use room back-ground for that purpose, or some other methods....

I would appreciate your feed back in advance.  You may send your respond to
my private address:     
farhad@ucla.edu 
or to Rad Safe, which ever way you prefer.  Thanks,

Farhad Semnani