Cochineal is unprocessed carmine.  It is currently used in some soft drinks.  It is used in Mayer's alcoholic cochineal stain for whole mounts of marine invertebrate larvae.  It is also used as a nuclear counterstain in Rinehart and Abul Haj's colloidal iron stain for acid mucins (Arch. Pathol. 52: 189-194).

   I have occasionally used tartrazine (F&DC yellow #5) as a collagen stain.

 

Allen A. Smith, Ph.D.

School of Graduate Medical Sciences

   Podiatric Medicine and Surgery

Barry University

Miami Shores, Florida