Uric acid from human urine

I read on this page that uric acid can be precipitated from urine by adding HCl(aq) to urine and leaving it to stand some time, after that the crystals of uric acid should precipitate.

http://www.books-about-california.com/Pages/Experimental_Organic_Chemistry/Ex_Organic_Chem_Chap_14.html

Is this true? Because I seen some methods on lambdasyn page which are a lot harder to do than this one.

Also, uric acid is similar to caffeine, maybe we could synthesize aminouracils from uric acid and then from that synthesize xanthanine and coffeine