(R20) Heidenhain’s hematoxylin working solution

Procedure

-     Mix equal parts of solutions A (R18) and B (R19), filter.

-     Let stand at room temperature for at least four hours (best, overnight) before use.

If the solution is used immediately after preparation, parasites will stain bright blue with little differentiation of nuclear details. The best results are obtained 3-4 days after preparation of the working solution.  

The working solution is stable for at least one week, but can be prolonged by storage in a sealed, dark glass flask. To check if the solution is still of good quality:

-       Add two drops of ammonium hydroxide in a test tube filled with tap water;

-       Add two drops of hematoxylin working solution;

-       If the resulting color is blue or blackish-blue, the working solution can be used, otherwise (if brown or brownish) the solution must be remade.