Hematology Exam 5 Flashcards
Advantage vs Disadvantage:
Are the following advantages of automated or manual?
- Speed
- Accuracy
- Precision
- Small blood volume
Automated
Advantage vs Disadvantage:
Are the following advantages of automated or manual?
- Low cost
- Fewer artifacts and spurious results
Manual
TRUE or FALSE:
Fewer spurious results and artifacts are seen with automated testing
FALSE
Manual testing has fewer spurious results and artifacts
Impedence and light scatter are types of ____________
Automation
Detects and measures changes in electrical resistance between two electrodes as cells pass through a sensing aperture.
Electronic impedance
aka
Current impedance
This automation method gives an initial 3 part differential (lymphs, mono-nucleated cells, and granulocytes)
Electronic impedance
aka
Current impedance
Cell counting:
The longer the current is disrupted, the ________ the cell.
The longer the current is disrupted, the BIGGER the cell.
Cell counting:
The frequency at which the current is disrupted = ?
The frequency at which the current is disrupted = # OF CELLS
What are the ways cells are counted and sized based on the degree and nature of light scatter?
- *-Absorption of light
- Diffraction
- Refraction
- Reflection**
DEFINITION:
Bending around corners of the surface of a cell
Diffraction
DEFINITION:
Bending because of a change in speed
Refraction
DEFINITION:
Backward scatter of rays caused by cellular obstruction
Reflection
LIGHT SCATTER:
What does 0 degree scatter tell us?
- *Cell volume - how big the cell is
- Diffraction of light**
LIGHT SCATTER:
10 degrees
Forward high angle cellular complexity
LIGHT SCATTER:
90 degrees
Degree of internal complexity (lobularity)
-Refraction and reflection of light
LIGHT SCATTER:
90 degrees depolarized
Cellular granularity
LIGHT SCATTER:
What angle tells us the cells volume/how big the cell is?
0 degrees
LIGHT SCATTER:
What angle tells us the cells complexity?
10 degrees
LIGHT SCATTER:
What angle tells us the lobularity of a cell?
90 degrees
LIGHT SCATTER:
What angle tells us the cellular granularity?
90 degrees deploarized
LIGHT SCATTER:
What angle is the diffraction of light?
0 degrees
LIGHT SCATTER:
What angle is the refraction of light?
90 degrees
LIGHT SCATTER:
What angle is the reflection of light?
90 degrees
TRUE or FALSE:
Increasing the number of RBCs counted produces a decreased precision
FALSE
Increased counted RBCs increases the precision
This reticulocyte parameter is used to determine the need for transfusion.
Immature reticulocyte fraction (IRF)
What is the immature reticulocyte fraction?
A ratio of immature reticulocytes to the total reticulocytes in a sample
What is the range for reticulocyte hemoglobin content?
28.2 - 36.6 pg
What does the reticulocyte hemoglobin content tell us?
Snapshot of iron availability
What is included in the power supply of analyzers?
-Pneumatics: compressed air operates pinch valves and vacuum pulls cells through orifices
-Electronics:
What does the diluter do on analyzers?
- *-Primary operating system
- Mixes, transports, pipettes, lyses, and senses**
What is the DMS?
Data management system
- *-Computer for the analyzer
- Displays, stores, and transmits information to printer
- Send results to laboratory information system (LIS)**
WBC histogram:
35-90 fL
Lymphs
WBC histogram:
90-160 fL
Mononuclear cells
WBC histogram:
160-450 fL
Granulocytes
Platelet histogram:
What is the range for particles measured?
2-20 fL
What is counted in the RBC bath?
RBCs and platelets
What is the dilution of the RBC bath?
1:6250
What happens in the WBC bath?
WBC count and hemoglobin is measured
What is the dilution of the WBC bath?
1:251 then lyse is added
TRUE or FALSE:
Three apertures count cells. At least 2 out of 3 have to agree.
TRUE
What are used as blanks for measurements on analyzers?
Isoton and lyse reagent
What tests are directly measured on analyzers?
WBC
RBC
HGB
PLT
NRBCs are counted as what on analyzers?
WBCs
How is MCV measured?
Through pulse height
Coulter Principle:
What cell size is counted as a WBC?
>35fL
Coulter Principle:
What cell size is counted as an RBC?
>36fL
What type of hemoglobin is measured on analyzers?
Cyanmethemoglobin
Calculation for hematocrit
RBC x MCV
______________
10
Calculation for MCH
MCH/RBC
Calculation for MCHC
HGB/HCT
Calculation for CV
SD
_________
MEAN x 100
What is the range in size for platelet counts?
2-20 fL
