1S [LAB] Specimen Collection, PBS Preparation, WBC Differential Count Flashcards
Artifactual morphologic changes in neutrophils begin to occur within ___ minutes of blood collection
30 mins
When EDTA-anticoagulated blood specimens are kept at room temperature, blood films should be made within ___ hours of collection to minimize storage artifacts
4 hrs
An in vitro phenomenon where platelets surround or adhere to neutrophils, which potentially causes pseudo-thrombocytopenia when counting is done by automated methods
Platelet satellitosis
It is the most convenient and most common method used for making peripheral blood films
Manual wedge technique
In manual wedge technique of PBS preparation, the pusher slide is held securely in the dominant hand at about a ___degree angle
30- to 45-degree angle
Wright-Giemsa stain is considered ___ because it contains both eosin and methylene blue
Polychrome stain
___ in the stain fixes the cells to the slide.
Methanol
The buffers added to the stain to maintain the specific pH
0.05 M sodium phosphate (pH 6.4)
Aged distilled water (pH 6.4-6.8)
Macroscopically, a well-stained blood film should be ___ in color
pink to purple
When the correct area has been selected, use of a back-and-forth serpentine, or “___,” track pattern is preferred to minimize distribution errors
battlement
Method of peripheral blood smear that is the simplest and most common
Two-slide or wedge method
In a proper peripheral blood smear, the film must cover ___ the length of the slide
2/3 to 3/4
Shape of a proper film in a peripheral blood smear
Finger shaped
This will accentuate poor leukocyte distribution by pushing larger cells to the very end and sides of the film
Moving the pusher slide forward too slowly
T/F: The slide may be labeled with a lead pencil on the frosted end or directly on the thinner end of the blood film
False (label should be at the thicker end of the blood film)
The thickness of the film can be adjusted by changing the ___ of the spreader slide or the ___ of spreading, or by using a ___ drop of blood
angle
speed
smaller or larger
An older technique of peripheral blood smear preparation that is now used only rarely for PBS but is sometimes still used for making bone marrow aspirate smears
Two-cover slip or Ehrlich’s two-coverglass method
Centrifuges that may be used to produce blood film that has uniform distribution of cells
Spinners
The ___ produces a uniform blood film, in which all cells are separated and randomly distributed
Spinner slide
Smears prepared using this method have white blood cells that can be easily identified at any spot in the film
Spinner method
An automated slide making and staining system
Sysmex SP-1000i
In Sysmex SP-1000i, the film is produced for every ___ seconds
30s
Prepares slide automatically from a single 90ul sample aspiration and up to 12 slides from a single sample presentation
DxH Slidemaker Stainer II Cellular Analysis System
The anticoagulant of choice for hematology cell counts and cell morphology
EDTA
Anticoagulant that causes blue background in wright staining
Heparin
Anticoagulant that distorts cellular morphology in wright staining
Oxalate and Fluoride
The RBCs should be ___ in color in a PBS
Pink to salmon
The nuclei should be ___ in color in a PBS
Dark blue to purple
The cytoplasmic granules of neutrophils should be ___ in color in a PBS
Lavender to lilac
The cytoplasmic granules of eosinophils should be ___ in color in a PBS
Red to orange
A gray/blue/green appearance is caused by stain or buffer being too ___ (acidic or alkaline)
Alkaline
A bright red/ orange appearance is caused by stain or buffer being too ___ (acidic or alkaline)
Acidic
Give the objective in the microscope:
Observes the overall quality of the film including abnormal distribution of RBCs, suggesting the presence of rouleaux or autoagglutination
10x
Give the objective in the microscope:
Rapid detection of large abnormal cells
10x
Give the objective in the microscope:
Quality control tool for validating WBC
40x or 50x
T/F: A nuclear chromatin of deep blue to black may be caused by underbuffing
False (nuclear chromatin is pale blue in underbuffered smear)
Color of the red blood cells if there is inadequate rinsing
Gray/ blue/ green
Specimen of choice for making a good blood smear
Capillary blood specimen
___ tend to occupy the edges of a smear
Platelets
Average size of neutrophils
12um
How many lobes does a neutrophil has?
3-5
Younger forms of neutrophil
Band neutrophil
The nuclei of band neutrophil frequently assumes a ___-shape
U
Normal neutrophil value
60-70%
Average size of eosinophils
13um
Normal eosinophil value
3-5%
Increased WBC in drug allergies and parasitic infections
Eosinophils
Normal basophil value
0-1%
Sometimes can be confused with neutrophils with toxic granulations
Basophils
Average size of monocytes
14-20um
The largest of the leukocytes
Monocytes
Single nuclei, partially lobulated, deeply indented or horseshoe shaped
Monocytes
Normal monocyte value
1-4%
Average size of lymphocytes
6-10um
Round nuclei that is deeply stained blue with visible chromatin
Lymphocyte
T/F: Sometimes, the nuclei of lymphocytes are indented
True
Normal lymphocyte value
20-30%
