Why does Orochimaru's Laboratory have this item to hand?


During episode 22, we see a test between Sarada's DNA and Karin's preserved
umbilical cord. I can understand Orochimaru being the type of person to keep
DNA on all his staff, but is there any symbolism, cultural significance or
plot reason why in particular an umbilical cord?




I don't think there is, my guess is that it's just a real life reference to
the medical field where umbilical cords are kept, as they have stem cells that
are helpful to treat some conditions.

Those cells can differentiate into different types of cells, which would give
some scientific base to some actions he has done, as injecting Hashirama's
cells.

