I would not waste my money on purchased yogurt. It is so easy to make, and at a fraction of the cost. This way you know what you have.
Of course for a while all dairy products will be suspect for carrying radioactive iodine in the USA. The risk will not be fully eliminated untill 80 days after the last discarge from Japan, or record of iodine found in water, food or the air in the USA
Please be advised
I advocate all health blogs linked to NMT.
Read them and explore MMS and CS.
It may be the best chance that you have to heal yourself
of long term and chronic illness.