AUTOMATION Flashcards
memorization
Developed by Coulter in the 1950s, and is the most common methodology used.
Electrical impedance
The number of pulses generated is _______ to cell count
proportional/ directly proportional
The amplitude of the pulse generated is ________ to cell size
proportional/ directly proportional`
More than one cell at a time passes through the orifice and causes artificial large pulses which results in falsely increased cell volumes and falsely decreased cell counts
Coincident passage
Uses flow cytometer with laser to measure light scattering properties of cells
Light scattering Optical method
In LSOM, forward angle light scatter (0 angle) measures:
CELL SIZE
Internal complexity or cell granularity
orthogonal/side angle LS
A combination of forward low-angle ls and forward high-angle ls which correlates to cell volume and refractive index or with internal complexity
Differential scatter
Forward low-angle light scatter: _____ degrees
Forward high-angle light scatter: _____degrees
Forward low-angle: 2-3 degrees
Forward high-angle: 5-15 degrees
The number of pulses generated is _______ to the cell count
Directly proportional
Optical scatter may be used to study ____, _____, and ______
RBCs
WBCs
Platelets
In the Histogram, the X axis represents the cell ____
while the Y axis represents the cell ______
X-axis = cell size
Y-axis m= cell count
In WBC histogram, the reference range of WBCs is:
35-450 fL
1st peak = cell(s) _______, smallest, measures ____fL
2nd peak = cell(s) _______, medium, measures ____fL
3rd peak = cell(s) _______, largest, measures _____fL
1st peak = LYMPHOCYTES; 35-90fL
2nd peak = MONOCYTES (includes Basophils and Eosinophils); 90-160fL
3rd peak= GRANULOCYTES (Neutrophils); 160-450 fL
Abnormal WBC histograms:
population before 35fL may indicate _______, _______
Population before 35 fL may indicate nucleated RBCs, giant or clumped platelets
Abnormal WBC histograms:
peak overlap at 90fL may indicate _______ or ______
peak overlap at 90 fL may indicate reactive lymphocytes or blast cells
Abnormal WBC histograms:
peak overlap at 160fL may indicate ________, ______, _____ or _______
peak overlap at 160 fL may indicate an increased in bands, immature neutrophils, eosinophils, or basophils
Reference size range for RBCs in histogram
> or equal to 36 fL
Abnormal RBC histogram:
Two peaks indicate a:
Dimorphic erythrocyte population
Abnormal RBC histogram:
Increased curve width will correlate with an:
increased RDW (anisocytosis)
Abnormal RBC histogram:
Shift to the right indicates:
increased MCV (macrocytic)
Abnormal RBC histogram:
Shift to the left indicates:
decreased MCV (microcytic)
reference size range for platelets in the histogram
2-20 fL
reference interval for the MPV:
6.8 to 10.2 fL
PARAMETERS:
RBC decreased
MCV increased
MCHC increased
HCT decreased
Grainy appearance
RATIONALE:
RBC agglutination
INDICATORS:
Dual RBC population or shift to the right on RBC histogram
Cold Agglutinins
Corrective action/remedy for cold agglutinins
warm sample at 37C
PARAMETERS:
Hb increased
MCH increased
MCHC increased
Lipemia, icterus, chylomicrons
Corrective action/remedy for lipemic specimens or chylomicrons present
Plasma replacement
PARAMETERS:
RBC decreased
HCT decreased
hemolysis
PARAMETERS:
WBC increased
Hb increased
Lysis-resistant RBC with abnormal Hb
Corrective action/remedy for lysis-resistant RBC with abnormal Hb
Manual dilutions, allow incubation for lysis time
PARAMETERS:
RBC decreased
Platelet increased
Microcytosis or schistocytes
Corrective action/remedy for possible presence of schistocytes
smear review
PARAMETERS:
WBC increased
Nucleated RBCs, megakaryocyte fragments, or micromegakaryoblasts
nRBCs or micromegakaryoblasts are counted as WBCs
PARAMETERS:
Platelet decreased
WBC increased
Platelet clumps
Corrective action/remedy for possible presence of nRBCs/ micromegakaryoblasts
Count nucleated RBCs or Micromegakaryoblasts per 100 WBCs and CORRECT
Corrective action/remedy for presence of platelet clumps
Redraw specimen in sodium citrate, multiply by 1.1
PARAMETERS:
Hb increased
RBC increased
HCT increased
INCORRECT/ABNORMAL INDICES
WBC >100,000/uL
Increased turbidity on Hb, WBCs counted as RBC COUNT
Corrective action/remedy for very high WBC count (>100,000/uL)
Spun hematocrit, manual Hb (read supernatant), correct RBC count, recalculate indices
PARAMETERS:
MCV increased
MPV increased
Platelet decreased
AUTOMATED DIFFERENTIAL MAY BE INCORRECT
Old specimen
RBC swell and as sample ages, platelets swell and degenerate, WBCs affected by prolonged exposure to EDTA
corrective action/remedy for suspected old specimen
Establish stability and sample rejection criteria
Errors with cell counting:
Aperture plug (negative or positive?)
positive error
Errors with cell counting:
Extraneous electrical pulses (negative or positive error?)
positive error
Errors with cell counting:
Improper setting of aperture current (negative or positive error?)
negative error/
(+/- error)
Errors with cell counting:
Bubbles (negative or positive error?)
positive error
Errors with cell counting:
Excessive lysing of RBCs (negative or positive error)
negative error
Giant platelets may be counted as RBCs or WBCs
true or false
true
Fragments of WBC cytoplasm may be counted as platelet or RBCs
true or false
true
Agglutination will cause a false positive result (RBC, WBC, platelet)
true or false
false - agglutination will cause a false negative result (RBC, WBC, platelet)
An increased number of schistocytes may make accurate RBC and platelet count possible
true or false
false - it may make RBC and platelet count impossible if there is an increased schistocytes
Agglutinated RBCs and platelets may cause a falsely positive count
true or false
true
Platelet satellitism will result in falsely high platelet counts and a decreased WBC count
true or false
false - platelet satellitism will result in a falsely low platelet count and an increased WBC count
Some abnormal RBCs tend to resist lysis, which may result in high WBC counts. Example sickle cells, extremely hypochromic cells, and target cells
true or false
true
FIBROMETER is an electromechanical device where fibrin strand formation is detected using a wire loop or hook that is incorporated to a fully-automated instrument
true or false
false - fribrometer is incorporated to a SEMI-AUTOMATED INSTRUMENT
Electra 750 and 750A is an AUTOMATED photo-optical device
true or false
false - Electra 750 and 750A is a SEMIAUTOMATED photo-optical device
Ortho Koagulab16S and 40 is an AUTOMATED photo-optical device
true or false
true
Computed values:
MCH
MCHC
HCT
Derived values:
MCV
RDW
MPV
PDW
Directly measured by electrical impedance:
RBC ct.
WBC ct.
PLT ct.
Flow cytometry components:
Laser (light source)
Fluidics
Computer
Detection system
3 part differential:
Granulocytes
Lymphocytes
Monocytes
