I take Betaseron, you add a diluent (salt water) to a vial with powder, gently mix, and then refill the syringe you started with. It is very easy to get bubbles when you refill the syringe. I have been told by several people (in medical field) not to worry about small bubbles, especially with sub-Q injections as Rebif and Betaseron is. I have a friend who takes Copaxone, as felly said, the task of getting rid of every single bubble big and small would either take forever or you'd end up with one sore finger from tapping. My Copaxone friend says " ah, those little bubbles won't hurt anything" Personally, in my case, not making the bubbles in the first place is LOTS easier than trying to get rid of them. I guess Rebif is different though.