I use the first drop and if the result seems off I will test again with a second drop. I always wash my hands with soap and warm water and dry on a towel that is only used for testing.. I clean my meter, the outside of my strips canister and my lancing device, weekly with Clorox wipes as recommended by the manufacturer to avoid contamination. If I use a home A1C test though. I always do use the second drop to make sure there is no chance of contamination. I think the reason the Drs office uses the second drop on a finger prick A1C test is that alcohol residue can throw off the results and they always clean your finger with alcohol first. If I have to use an alcohol pad to clean my finger to test when away from home, I wipe the alcohol off with a clean tissue before I stick myself.