load 1 cc into each vial before you start
the reason behind that is if there is if you just keep drawing, the vial will act like a vaccum and suck the oil back in it (which would suck if your test vial sucked the deca from your syringe into it)... same thing goes if there is too much air in the vial it will push air/oil into the syringe
make sure you use a different needle to draw, otherwise it will be dull by the end of all that.... also i like to draw the water, based Anabolic Androgenic Steroids (AAS) before the oil based, since bacteria can easily grow in H20... if your not using a water based Anabolic Androgenic Steroids (AAS) it doesnt matter