Section 2: Peripheral Smears Flashcards
What is the purpose of the buffy coat smear procedure? How would not doing a buffy coat smear affect your cell counting?
To concentrate WBCs for easier differential counting. No buffy coat smear makes it harder to count WBCs because they would be sparser. Concentrating the cells makes counting easier
Which Romanowsky stain is used to make peripheral blood and bone marrow smears?
Wright or Wright-Giemsa stain
What is the principle behind the Wright stain?
Opposites attract. Uses basic and acidic dyes to visualize and ID blood cell types under a microscope
What are the ingredients and staining properties of the Wright stain? pH of buffer?
Methylene blue = basic dye that stains acidic structures (such as DNA). Stains basophilic structures.
Eosin red = acidic dye that stains basic structures. Stains acidophilic structures.
Phosphate buffer (pH 6.4-6.8)
How does water artifact affect the stained smear and how can it be avoided?
It compromises cell morphology. May see crenation, pallor, moth-eaten spiky look. Avoid over-drying. Limit drying to 15 minutes
How would you trouble shoot if your microscopic stain is too blue? Possible causes?
Maybe stain or buffer too alkaline, over-stained, or under-rinsed
How would you troubleshoot if your microscopic stain is too red? Possible causes?
Stain or buffer too acidic, under-stained, or over-rinsed
Cause(s) of macroscopically super blue smear?
High protein concentration, particularly Ig
If macroscopic holes present, what may cause it?
Abundance of lipids, sometimes protein
If macroscopic grainy clumps present, what may cause this?
RBC agglutination
List 6 artifacts
Water
Crenation
Smudge cells
Pyknotic degeneration
Fibrin strands
Scratch mark
What is Crenation?
Excessive drying leads to wrinkly cells
What are smudge cells? How to solve?
Cells with degraded membrane but intact nucleus. Caused by increased cell fragility. Solve by adding albumin to stabilize proteins
What is pyknotic degradation? What does this indicate?
Apoptotic cells. Chromatin pattern loss. Nucleus breaks down first so granules left. May indicate old sample greater than 5 hours old
Which artifact is confused with nucleated RBCs?
Pyknotic cells
