Sudan Black B System

Reagent Preparation

Glutaraldehyde fixative is prepared by adding 25 mL reagent grade acetone to 75 mL Glutaraldehyde solution. Tightly cap and store at 2-8 ºC. Stable for several months but discard if turbidity develops.


  1. Fix smears or films in chilled Glutaraldehyde fixative (2-8 ºC) for 1 minute with gentle agitation.
  2. Rinse thoroughly in deionized water.
  3. Stain slides in Sudan Black B reagent for 5 minutes using intermittent agitation.
  4. Rinse slides 3 or more times in 70% ethanol until no more dye washes out.
  5. Rinse slides thoroughly in deionized water.
  6. Counterstain in Gill’s Hematoxylin No. 3 for 5 minutes.
  7. Rinse slides thoroughly in tap water and allow to air dry.
  8. Coverslip slides with permanent mounting media.


Neutrophils and their precursors show blue-black intracellular granulation. Monocytes stain less intensely and lymphocytes do not stain with Sudan Black B.

Sudan Black B System


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