When drawing test from a multi-dose vial, I will use an 18-gauge needle and then swap it with a brand new 23g needle to inject into the muscle. After drawing the test into the syringe, I replace the cap on the 18g needle, remove it from the syringe and keep it for future use. This morning, when I uncapped the 18g needle to draw, I noticed a little test was dripping down the side of the needle. I wiped it off with a cotton swab, but I did not dip the cotton swab in alcohol, because I was afraid the alcohol residue would kill the test inside the vial.

I did, however, clean the rubber stopper with alcohol before sending the 18g needle into the vial. I always use a brand new 23g needle for the injection. Should I be worried about infection or contamination to the test in the vial? This is the first time I re-used a 18g needle to draw. I always clean my skin with alcohol before and after inject as well. If I am the only one using these needles, do I have much to worry about in terms of infection? Does the cap on the 18g needle protect it from contamination?