Have you tried Snook's retic?  It is oh so easy, and it works wonderfully!  
We use tonsil/lymph node as control...I believe spleen would work very 
well,too.

When doing the Snooks method, try to titrate the ammoniacal silver to the 
point that it is still a little cloudy (not clear).  This works wonders!

Good luck,

debra flynn
jackson, MS