Re: Orphan Black kept my Attention.
Guessing that the woman we only see the silhouette of that Leeky was talking to on the phone is another clone. At least to me it looked like Sarah's physique.
I think that DNA sequence is also more than a marker. It's probably the actual experiment. Cloning is the control, splicing in different patches of DNA in the same spot is what they are watching for different results.
Baby, you and me were never meant to be, just maybe think of me once in a while...