|MadSci Network: Medicine|
Hey Dave.. The FORMALIN TEST measures the analgesic (painkilling) effects of medications on so-called tonic, or persistent pain. A dilute solution of formaldehyde and saline is injected under the skin of a rat's paw, inducing pain that lasts for about 90 minutes. The rat licks its paw repeatedly, which is a sign of moderate pain (a pain rating of 3). Then. after a while, the animal holds the paw in the air (a rating of 2), steps on it gingerly (a rating of 1) and finally walks normally (a rating of 0). These criteria are used in testing the effectiveness of analgesias.... Mark
Try the links in the MadSci Library for more information on Medicine.