Situation: reticulin stain nonspecific staining (black precipitate; grayish discoloration of all tissues)
Risk factors for nonspecific staining:
(1) dirty glassware
(2) use of metal instruments when preparing the reagents or during the staining process
(3) fixative that contains a heavy metal
(4) pH of the impregnating solution less than 11.0
(5) outdated solutions
(6) suboptimal water
Recommendations:
(1) Glassware should be cleaned carefully, which may include acid washing.
(2) Use only clean plastic and glass instruments in preparing reagents and when staining.
(3) The tissue fixative should be metal free.
(4) The pH of the impregnating solution should be carefully maintained.
(5) Use freshly made solutions.
(6) Use double distilled water at all stages.
