The May-Grunwald Giemsa (MGG) stain is used for cytological examination. It involves a two-step staining process using May-Grunwald stain followed by Giemsa stain. May-Grunwald stain induces an orthochromatic staining of cell components in pink/orange/blue/purple hues. Giemsa stain then induces a metachromatic staining, dyeing azurophilic components red. The stained smears are examined under a microscope, with nuclei appearing blue, cytoplasm pink/rose, and bacteria blue. The pathologist then interprets the results.

1. MAY GRUNWALD GIEMSA (MGG) STAIN
PURPOSE: Cytological examination.
PRINCIPLE OF THE METHOD: May-GrunwaldGiemsa(MGG) stainingisa mixture of twonwutral stains:
- May-Grunwaldstaincomposedof anacidicstain(eosin)andabasic stain(methylene blue)
- Giemsastaincomposedof eosinandanothermetachromaticbasicstain:azure of methylene
The firststaininducesan orthochromaticstainingoncell components(pinkororange dye foracidophilic
componentsandblue orpurple forbasophilicandneutral components).The secondinducesa
metachromaticstaining:reddye forazurophiliccomponents.
TYPE OF PRIMARY SAMPLE: Fine needle aspirate.
EQUIPMENT: Disposable 22Gneedle
Disposable 10ml plasticsyringe withpiston
GlassSlides
Cottonswab
Rectifiedspirit
REAGENT:
 May-Grunwald’sstain
 Giemsastain
 Methanol
PREPARATION OF STAINS
May GrunwaldReagent:Workingsolution:StockSolution10ml + Distilledwater10ml (1:1)
GiemsaSoution:Workingsolution:StockSolution10ml + Distilledwater 90ml (1:9)
STAINING PROCEDURE
 Fix air driedsmearsinmethanol for5 minutes
 Stainthe fixedsmearsinMay-Grunwaldsolutionfor10 minutes
 StainwithGiemsaworkingsolutionfor15minutes
 Wash inrunningwater
 Dry inair
 Clearinxylene andmountDPXwithcoverslip

2. QUALITY CONTROL PROCEDURE:
The detailedqualitycontrolledprocedureismentionedinChapterIII.
LIMITATION:
 Needle hasmissedthe targetinitially.
 Needle incentral cystic/necrotic/haemorrhagicareadevoidof diagnosticcells.
 Needle samplingadominantbenignmassbutmissingasmall adjacentmalignantlesion.
 Fibrotic/desmoplastictargettissue givingascant cell yield.
RESULTS AND REPORTING:
Nuclei stainblue,cytoplasmstainspinktorose,andbacteriastainblue.
Pathologistchecksthe stainedsmearsandinterpretsthe resultsaccordingly.
REPORTABLE INTERVAL OF EXAMINATION:Normal 12-24 hours(max.4 days).Emergency6-8hours.
SAFETY PRECAUTION: DetailedsafetyprecautionsinchapterIV.
RECORD MAINTAINENCE:
The slidesare maintainedinthe sectionfor6months.
The reportsare directlyrecordedinthe worksheetregister.The reportingregisterisretainedinafile.
DOCUMENT REFERENCE:
1. Koss’DiagnosticCytologyanditsHistopathologicBases,5th
edition.
2. Svante R. Orell,GregoryF.Sterrett,Fine NeedleAspirationCytology,5th
edition.