Peripheral Smear

Peripheral smear

Preparations • Specimen-direct capillary blood or anticoagulated blood • Apparatus-clean glass slides,lancet, spreader slide,microscopeµscope oil • Stain-leishman stain,wright or gimsa • Diluent-distilled water or buffer solution with Ph 6.8

Composition of leishman’s stain • • • •

Polychromed methylene blue Eosin azure leishman powder Acetone free absolute alcohol 1.5gms leishman powder in 1 liter acetone free absolute alcohol

Procedure MAKING A SMEAR • One drop of blood on one end of slide • Spreader slide is placed at 45°on the drop and moved along the slide • It is moved smoothly and once such that the blood film is thin • Care should be taken to prevent the formation of air bubbles • Air dry the smear • Make identification mark on one edge

Staining a smear • Place the smear on the staining rack • Pour leishman stain to cover the smear completely allow to fix for 2-3 mins • Add water twice the amount of leishman’s stain allow to fix for 7-10 mins • Appearance of golden scum or sheen on the surface of stain • Wash the stain off the slide with running water • Wipe the back of slide and air dry the slide

Examination of the smear • The stained slide is placed on the microscope and is focused under low power • Place a drop of oil on the slide and observe under oil immersion objective • Observe RBC,platelet series • WBC series is observed and a differential count is done • Record the findings

Precautions • Objective must be clean • Objective must be cleaned after every use • Good smear is tongue shaped occupying 2/3rd of the slide • Divided into head,body and tail • Must be focused at the junction of body and tail

Diagnostic value RBC’s SERIES • Size-microcytic/normocytic/macrocytic/ anisocytosis • Shape-poikilocytosis,sickle cells,target cells,tear drop cells,burr cells spherocytosis,ovalocytosis • Color-hypochromic/normochromic • Immature cellsnormoblasts,polychromatophillic cells

WBC’s SERIES DIFFERENTIAL COUNT • Neutrophills-40--70% • Eosinophills-2--4 % • Basophills-0--1 % • Monocytes-2--4 % • Lymphocytes-25—40 %

Immature cells

• Myeloid seriesmyeloblasts,promyelocyte,myelocyte,met amyelocyte,band forms • Lymphoid series-lymhoblasts

Thank you

PLATELET SERIES • General score-6--10platelets/oil immersion field PARASITES • Intracellular-malarial parasite • Extracellular-microfilarial