agar agar is used in labs to culture out all sorts of wonderful bacteria. Frequently with blood added, the little bugs just flock to it! an algae product. Used in ice cream also to help with the smooth consistancy.
Jello is an irreversable hydrocolloid in that once it sets up. it can not be made into a liquid again and then re-geled. Agar agar can be re-geled. Also they don't use blood in jello brand products, at least to my knowledge, like they do to lots of culture mediums using agar-agar.
Speaking of cultural mediums, wonder if jo9hn has made peace with opera yet? Or, most likely, ooera, as well as jello, is just rubbish.