Making and Staining Smears

peripheral blood smear

allows technologist to evaluate a patient’s RBCs, WBCs, platelets, RBC parasites, and morphology in the natural state

RBCs

WBCs

platelets

RBC parasites

morphology

what is evaluated in a patient’s peripheral blood smear in the natural state

morphology

structure of cellular elements

evaluation of a stained blood smear

aids physicians in the diagnosis and monitoring of diseases such as leukemia, sickle cell anemia, thalassemia, and malaria

leukemia

sickle cell anemia

thalassemia

malaria

evaluating of a stained blood smear aids physicians in the diagnosis and monitoring of these 4 diseases specifically

cell’s structure and distribution

these must be altered as little as possible during the preparation of the blood smear

EDTA

typical anticoagulant used for preparing a blood smear

blood from fingertip (capillary collection)

other method of blood collection for peripheral blood smear

morphology

use of other anticoagulants other than EDTA may alter the cell ?

making blood smear

1. 1 drop of EDTA whole blood is dropped on one end of the slide

2. spreader slide (30-45 degree angle) is placed in front of the blood drop, pulled back into the drop, blood is allowed to spread across the width of the spreader slide, then pushed forward to create a feathered edge

consistent pressure

it is important to maintain ? when making a blood smear

wedge smear

most common smear

smear should cover 1/2-3/4 of the slide

gradual transition from thick to thin

no holes or ridges

a feathered edge

components of a good blood smear

stains

applied to prepared blood smears to make the cellular elements visible for

WBC distribution

RBC morphology

parasite detection

stained smears are evaluated for the these three components of a blood smear

differential

evaluation of the WBC distribution in a blood smear

evaluation of a blood smear

often leads to a diagnosis or verification of disease

wright-giemsa stain

eosin and methylene blue are used

“polychromatic”

peripheral blood smear

allows us to identify cells and morphology

eosin

an acidic stain that stains the basic portion of a cell pink/red (ex. granules in eosinophils)

wright-giemsa stain

stain used in lab

methylene blue

basic stain that stains the acidic portion of the cell blue (nucleus)

accurate interpretation of cellular morphology

well-made and well-stained slide is necessary for ?

2-3 hours

slides are prepared within ? of blood collection

RBCs should be pink to salmon color

nuclei are blue to purple

cytoplasmic granules of neutrophils are lilac

cytoplasmic granules of basophils are dark blue to black

cytoplasmic granules of eosinophils are red to orange

area between the cells should be clean and free of precipitated stain

how a properly stained blood smear should look

lilac

color of cytoplasmic granules in neutrophils

dark blue to black

color of cytoplasmic granules in basophils

red to orange

color of cytoplasmic granules in eosinophils

pink to salmon

color of RBCs

blue to purple

color of nuclei

clean

free of precipitated stain

the area between the cells should be ? and ?

automatic stainers found in labs today

utilize a moving belt or another batch stain method

automation

blood smears are stained, rinsed, and dried for the technologist by ?

multiple sliders may be stained at the same time

advantage of automatic stainer

if there is a problem with the staining equipment or the stain pack, it is not evident until multiple slides have been processed

disadvantage of automatic stainer

Hematek automated stainer

stainer used in lab

examination of peripheral blood film

1. Start on 10x, look for abnormal distribution of cells, Rouleaux, and RBC agglutination

2. Change to 40x for a WBC estimate. Count WBC in 8-10 fields, then multiply by 2000

3. Change to 100x oil immersion for a WBC count. Choose an area on the slide where cells are almost touching. In a serpentine pattern, count 100 WBCs. Record the number of cells counted as a percent

4. Absolute counts are determined by taking the percentage of a cell

abnormal distribution of cells

rouleaux (stacking)

RBC agglutination

what to look for at 10x

rouleaux

stacking of RBCs

WBC estimate

what to look for at 40x

count WBC in 8-10 fields

then multiply by 2000

how to complete WBC estimate

WBC count

what to look for in 100x

choose area on slide where cells are almost touching

use serpentine pattern and count 10 WBCs

record number of cells counted as a percent

how to complete WBC count

percentage of cells

absolute counts are determined by taking the ?

ex. 0.7 x total count

anisocytosis

poikilocytosis

elements of RBC morphology to look for in blood smear

RBC morphology

should match the RBC indices reported on the analyzer printout

scan 10 fileds

average the platelets seen

multiply by 20,000

how to perform platelet estimate

150-450 × 10³/ mm³

normal range of platelets

polychromatic stains

stain that uses multiple dyes to color different components of the cell