Purification

Another way of circumventing close prior art is to draft the claims to expressly recite some level of purification. For example, U.S. 6896910 claims a concentrated water extract of a combination of herbs.

9. The agent according to claim 8, wherein said agent is formulated into powder, granules, tablets, capsules, a solution, suspension, solution for injection, jam, syrup, essence or a concentrated solution.

U.S. 6890574 recites a concentrated solution of an old product (tomatoes), and further recites a mental step of adding the concentrate "as a taste enhancer".

1. A method of enhancing the flavor of foods comprising adding a clear tomato concentrate as a taste enhancer to the food in a quantity sufficient to enhance the flavor of the food and in a sufficiently small amount so that no tomato flavor is imparted to the food, said clear tomato concentrate consisting of a hydrolyzed and concentrated tomato serum.

Here's another example, from U.S. 6869625 :

11. A purified composition comprising an effective amount of an Argyrolobium roseum extract, wherein said extract comprises a flavonoid glycoside compound.

The same concept is applied in reciting an "isolated" nucleic acid , bioactive composition, cell, etc.

1. An isolated nucleic acid consisting of the sequence of SEQ ID NO: 5.