4. Making a Blood Smear

What is necessary for accurate evaluation of a blood specimen?

A properly prepared blood film.

What are the optimal timeframes for preparing blood smears in EDTA?

Made within 1-3 hours, microtainers within 1 hour of collection.

What color appears for red blood cells in a well-stained peripheral smear?

Red-orange.

How should white blood cells appear in a stained blood smear?

With blue-purple nuclei and red-purple granules.

What is essential for evaluating white blood cell types and morphology?

A good counting area in the smear.

What must be done when automated differentials do not meet criteria?

The technologist must perform a manual differential count.

What does a good slide appearance not feature?

Streaks, ridges, troughs.

How much of a slide should ideally be occupied by the smear?

Approximately 2/3 of the length of the slide.

What is a necessary label on the blood smear?

Patient name and unique identifiers including specimen barcode.

What angle is preferred for making a wedge smear?

30-45 degrees.

Why is a proper technique important in blood smear preparation?

For accurate diagnostic results.

Name one cause of a poor blood smear related to blood storage.

Prolonged storage of anticoagulated whole blood.

What are dirty slides likely to cause?

Uneven preparation of the blood film.

What is a potential consequence of delaying blood smear preparation?

Large cells will locate near the feather edge.

What happens if the spreading angle of the slide is increased too much?

The smear will be too thick.

How does humidity affect blood smears?

High humidity can prolong drying and distort erythrocytes.

What can result from not allowing the slide to dry properly?

Drying artifact.

What is one cause of burr cells (echinocytes) in a smear?

Old blood or inadequate drying.

List one of the causes for poorly made blood slides.

Not letting blood spread before pushing.

What indications suggest a smear is too thin?

RBCs look like spherocytes.

What should be checked for too thick blood smears?

Counting area size and RBC overlap.

What can excessive tails indicate on a blood smear?

Improper spreading technique.

What is the effect of the angle of the spreader slide on blood smear?

It depends on the size of the blood drop and viscosity.

What is the optimal angle for spreading?

30-45 degrees.

What is essential for optimal cell examination in a blood smear?

A feathered edge.

What are the limits of blood smear preparation regarding blood viscosity?

Higher hemoglobin requires a lower angle for the smear.

What can improper cleaning of glass slides result in?

Imperfect cell distribution.

Why must blood smears be made immediately after contact with the slide?

To avoid clumping and uneven distribution of cells.

What is the appearance transition from point of origin to termination in a good smear?

Thick to thin with a uniform edge.

How should a blood smear appear overall?

Smooth without waves or gaps.

What should the technologist document when making a smear?

Initial of the technologist making the smear.

What is the recommended feature of the counting area?

At least 10 fields where 50% of RBCs do not overlap.

What does a smear with a notched edge indicate?

Possible poor technique in spreading.

In a blood smear analysis, what might an increased number of neutrophils suggest?

Infection or inflammation.

If the blood smear is too long, what adjustment must be made?

Decrease the angle of the spreader slide.

What is a common issue with too thick blood smears?

Inaccurate white blood cell differential.

What feature does a good smear have aside from the right thickness?

Absence of clumps.

What type of cells does a poorly made smear often misrepresent?

Likely to misrepresent the morphology of red blood cells.

What is crucial in the timing of blood smear preparation?

Immediate preparation after sample collection.

How does blood viscosity affect smear spreading?

Higher viscosity requires a higher angle to avoid a smear that is too short.

What tool is often used to create a blood smear?

A clean glass slide.

What is the effect of letting blood sit too long before making a smear?

Cells may clump and dry unevenly.