Techniques for blood collection from the rat include puncture of the heart, retro-orbital plexus, jugular vein, saphenous vein, tail blood vessels, carotid artery, abdominal aorta, and vena cava.

For the first time, however, experts succeeded in visually tracking the movement of microplastics through brain blood vessels in mice—and the pile-ups resembled a microscopic “car crash.” ...