[Histonet] Azure B as a counter-stain for melanin

[Margaryan, Naira]

Dear Histology Professionals,

I am using the Azure B as a counter-stain for melanin preparing solution by the protocol below. My questions are:
1. Is this solution should be fresh prepared every day?
2. How long I can store and use this solution?
3. Where this solution should be stored in the room or in the refrigerator?

My protocol is:
            Counterstain Method
      The use of Azure B as a counter-stain will stain melanin a blue green color.
            Azure B working reagent:
            4mL of a 25mg/mL aqueous solution of Azure B
                        3.4mL of 0.1M acetic acid
                        600uL of 0.1M sodium acetate
                        27mL of DI water
                        5mL acetone

                        Incubate for up to 30 minutes, followed by a 20-second hematoxylin counter-stain.  The use of either counterstain should give you good cytological detail, with blue-green melanin and brown DAB specific signal.

Thanks in advance,
Naira