Wear a pair of gloves before proceeding to fit and secure the rat in the custom made rat jacket. Then using one hand hold the rat jacket's middle and back portion on the table. Using the other hand, gently hold the rat by its tail to pick it up from the feeding cage and place it into the jacket as the rat moves forward into the jacket and its head reaches the headgear point.
Using both hands, carefully pull out its left and right upper limbs from the holes in the jacket. Securely wrap the tying ropes from the opening end of the jacket around the rat's trunk, and tie them tightly at the opposite end to adequately restrain its upper limbs. Tie the rope loose enough to prevent hypoxia or local limb ischemia, and tight enough to prevent the rat's escape.
In a similar manner, secure its lower limbs.