HI robert
with my biopsy they did they other side. My weak side is left and they went to right quad. I asked the docters and they said they do that so if there was a problem (infection or something) it would not make a weak leg worse. She said it would show(disease) anywhere from where it was taken. this is just what they told me. I went with the full Knock-out on mine, but had to be brought awake because I stopped breathing. So even the twillight was fine. Be ready for some pain the first 48 hrs, I was not expecting it! I was walking and lifting 2 days after a c-section!!! I thought I would be golfing the next day....no. Good luck!