Go with the flow

If you're into handcrafted blood cells, here's something.

Choose oxygenated (bright red) or deoxygenated (dark red).

Is anyone still with me?

Says the seller:  "Great gift for that biologist or hematologist in your life."

Crocheted Oxygenated and Deoxygenated Blood Cells:
http://www.etsy.com/view_listing.php?listing_id=23449803#