Wright Stain, Unbuffered

Reagents for this procedure are sold as individual stain solutions and are available for purchase under separate part numbers with storage requirements and expiration date designated per bottle.

Product Options:

Part # Non-Kit


SOLUTION: 500 ml 1 Liter 1 Gallon
Wright Stain Solution Part 1420A Part 1420B Part 1420C

Additionally Needed:           

Alcohol, Methanol Anhydrous, ACS Part 12236
Wright Stain Buffer Solution, pH 6.8 Part 1430

For storage requirements and expiration date refer to individual bottle labels.



Newcomer Supply Wright Stain, Unbuffered for Smears is used for differential staining of cell types in peripheral blood smears as well as bone marrow smears/films.



Technique: Flat staining rack method

Solutions: All solutions are manufactured by Newcomer Supply, Inc.



  1. Prepare within an accepted time frame, a well-made blood smear or bone marrow smear/film per your laboratories protocol, with a focus on uniform cell distribution.
  2. Allow slides to thoroughly air-dry prior to staining.
  3. Place slides on a flat staining rack suspended over a sink.
  4. Fix smear by flooding slide with methanol for 10-30 seconds.
  5. Shake off excess methanol; flood each slide with 1 ml Wright Stain Solution for 3 to 5 minutes.
  1. Filter Wright Stain Solution prior to use.
  2. See Procedure Notes #1 and #2.
  1. Retain Wright Stain Solution on slides, directly add 1 ml of Wright Buffer Solution, pH 6.8 to each slide; gently agitate to mix. Stain for an additional 6 to 10 minutes.
  2. Wash well in distilled water; rinse thoroughly in running tap water.
  3. Air-dry slides in a vertical position, then examine microscopically.
  4. If coverslip is preferred, allow slides to air-dry and coverslip with compatible mounting medium.



Erythrocytes Pink
Neutrophils Granules - Purple
Eosinophils Granules - Pink
White blood cells Chromatin - Purple
Lymphocytes Cytoplasm - Blue
Monocytes Cytoplasm - Blue
Bacteria Deep Blue



  1. The timings provided in this procedure are suggested ranges.  Optimal staining times will depend upon staining intensity preference.
  2. Smears containing primarily normal cell populations require minimum staining time; immature cells may require a longer staining time. Bone marrow smears/films may also require a longer staining time.
  3. The color range of the stained cells may vary depending upon the pH of the buffer and the pH of the rinse water used.
  1. Alkalinity is indicated by red blood cells being blue-grey and white blood cells only blue.
  2. Acidity is indicated by red blood cell being bright red or pink and lack of proper staining in white blood cells. 
  3. If necessary adjust buffer pH accordingly to 6.8 +/ - 0.2.



  1. Lillie, R. D., and Harold Fullmer. Histopathologic Technic and Practical Histochemistry. 4th ed. New York: McGraw-Hill, 1976. 747-748.
  2. McPherson, Richard and Matthew Pincus. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia:  Elsevier Saunders, 2011. 522-532.
  3. Sheehan, Dezna C., and Barbara B. Hrapchak. Theory and Practice of Histotechnology. 2nd ed. St. Louis: Mosby, 1980. 154-155.
  4. Modifications developed by Newcomer Supply Laboratory.