"flesh of my flesh; blood of my blood; kin of my kin"
The Creation of Eve
Creative Commons Attribution Share AlikeThe Creation of Eve - Credit: Georges Jansoone/Wikimedia Commons

This seems to be a reference to the Biblical creation of woman (Genesis 2:23-24), when Eve was made using one of Adam’s ribs:


And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man.

Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.


 Dracula is insinuating that he has re-made Mina in his own image – a vampire!