I like the "infinity" logo in #17 better than the "DNA" logo in #14, but I wonder about creating a hybrid? I am doing anti-aging medicine including stem cell therapy, so DNA is very important and this is a great design element that no-one else has thought of. I also prefer if the "Inc" is more subtle (lighter font or different colour) than the "Dr G Pagdin", as in #7. I do want to include the tag line "Living Longer Better", so my favourite of your entries is #17. Great work!
I like the newer contributions: brighter and more confident. The italics definitely adds energy! I like the DNA strand in #50 better than 51, but I like the underlining in #51, with "Inc" below rather than above. Could you combine those elements?