Lapis ISSN 2398-2969
Staining technique: Romanowsky stains - overview
Contributor(s): Molly Varga, Sarah Pellett
- The choice of stain used is dependent on availability of equipment and staining solution in practice, the experience and preference of the clinician.
- Stains can be either applied manually with the aid of cuvettes, or mechanically in automated staining systems.
- Romanowsky stains are neutral stains composed of a mixture of oxidized methylene blue (azure) dyes and eosin Y.
- Romanowsky staining is the prototypical cytological staining method. Changes in the methodology have lead to the evolution of other linked staining methods.
- Romanowsky stains include Wright's, Giemsa, Wright-Giemsa, May-Grunwald-Giemsa and Diff-Quik.
- Buffer is essential to enable the dyes to precipitate out of the solution and bind to sample material.
- The azures are basic dyes that bind acid nuclei and result in a blue to purple color.
- The eosines are acidic dyes that are attracted to the alkaline cytoplasm, producing red coloration.
- They generally provide excellent nuclear detail and also clear differentiation of the cytoplasm.
- The alcohol based 'fast' staining kits such as Diff-Quik are readily available and commonly used in practice.
- Bone marrow examination.
- Blood films.
- Stain cells to identify abnormalities in morphology and pathological changes.
- Easy to prepare.
- Readily available.
- Nuclear and nucleolar detail not as defined as Papanicolaou stain. Is adequate to distinguish neoplasia from inflammation.
- pH sensitive - buffer essential.
- Can get variation in coloration with a change in staining times and pH.
- Recent references fromPubMedandVetMedResource.
- Cray C & Zaias J (2004)Laboratory procedures.Vet Clin Exotic Anim Pract7(2), 487-518PubMed.
Other sources of information
- Merck KGaA (2013)Cytodiagnosis Staining Methods.Merck Millipore Manual. Website:www.merckmillipore.com.
- Dunn J K & Gerber K (2005)Diagnostic Cytology. In:BSAVA Clinical and Feline Clinical Pathology. 2nd edn. Eds: Villiers E & Blackwood L. BSAVA, Gloucester. pp 305-339.
- Dacia Sir J V & Lewis S M (2001)Practical Haematology. 6th edn. Longman Singapore Publishers Pte Ltd. pp 50-61.
- Mary Pinborough, Pinmoore Animal Laboratory Services Ltd, The Coach House, Town House Barn, Clotton, Cheshire CW6 0EG, UK. Tel: +44 (0)1829 781855; Email: firstname.lastname@example.org ; Website: www.palsvetlab.co.uk .