automated counters

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What machine measures MCV and calculates the hematocrit?: Sysmex.
What machine measures Hct and calculates the MCV?: Coulter.
which analyzer does not use light scatter?: Sysmex.
Which analyzer has to manipulate eos/basos to differentiate them?: sysmex.
which analyzer has von behren's plates instead of sweepflow?: cell dyn
what is the principle of the cell dyn?: cells are passed between plates with apertures of different size; prefer to flow through the larger, and get counted.
which analyzer uses DC/RF for volume determination and differentiation?: sysmex
is there a chance of coincidence loss on the cell dyne?: yes; to correct, use pulse editing.
which analyzers seperate a section of cells for hemoglobin via cyanmethemoglobin colorimetry?: all of them
what two ways are white cells counted and differentiated on the cell dyne? (2 acronyms): WIC - white cell impedence cnt.
WOC - white cell optical count.

the first uses impedence, the second uses light scatter.
what is different between the sysmex 9000 and 3000?: 9000 uses DC/RF; the 3000 does not use RF for differentiation, but instead light scattering.
what is cell dyn's claim to faim?: WIC and WOC - two counts based on impedence, and light scatter.
what angles does the cell dyn scatter light?: FAS - forward
orthogonal - 90, right angle
depolarized
10 - narrow angle
On Celldyn, what does the FAS measurement tell you? -90 right angle? -90 depolarized? -10?: FAS = the size of cell
right angle = granularity
depolarized = eosinophils
10 = n:c ratio - nucleus density
what type of sheath fluid is in the cell-dyn?: weak salt that pulls hemoglobin out of cells so there's no interference.
what type of light source is used in the cell-dyn?: polarized helium argon laser.
what is the acronym for the special light scattering used in the cell dyn?: MAPSS - multi angle polarized scatter seperation
what is list-mode analysis?: whatever electrical information is gathered from each cell is given in a direct plot, not a box scatterplot.
which analyzer shows exactly whre basophiles are in the electrical information?: cell-dyn, don't have to rotate the scattergram to visualize them.
what is advia technology based on? what is it NOT based on?: light scattering
cytochemical staining

not on electrical impedance.
is advia good? what is it good at?: no; it's unwieldy and difficult to interpret;
give the best RBC information
What do cold agglutinins do to an analysis?: cause RBCs to clump and give an abnormal RBC count;
Hct will be wrong, but Hgb will be normal because cells are lysed.
how do you fix cold agglutinins?: warming the sample and rerun it.
What causes a high take-off?: anything smaller than a lymph.
specific things that cause high takeoff?: -Platelet clumps
-Fibrin strands
-nRBC
-Cryoglobulins
if you have nRBCs, what do they do to the analysis, and how do you correct it?: will cause a high-take-off. do a manual diff and correct for the nRBCs.
if you have platelet clumps, how do you correct?: do a manual platelet count.
when the WBC count is over 90000 cells/uL, what happens to the analysis? How do you correct it?: invalidate the WBC count;
to correct, dilute the sample and rerun it.
if the WBC count is greater than 2% of the RBCs, what does this mean?: You must correct the RBC: subtract two percent of the RBC from the old RBC count for a new one.
What are the effects of a high WBC count?: -falsely elevated HgB (cloudy)
-incorrect RBC and MCV
-Hct must be spun, not calculated.
what stain is used in normal retic counts?: new methylene blue
what occurs in an automated retic counter? (process): 1. cells are stained/incubated.
2. in weak H2SO4, cells lyse, Hgb escapes, and a ghost with precipitated RNA remains.
What are the 2 major types of automated retic counters?: R-3000 by Sysmex;

Advia Retic counter
What type of dye does the sysmex use?: Auromine-O flourescent dye.
what type of dye does the Advia retic counter use?: Oxazine 750
what type of technology does the Advia retic counter use?: Light scattering - at three angles.
What does IRF refer to?: the advia's zones for high and medium staining retics; was used as an indicator of whether a bone marrow graft was successful.
what's the difference btwn the Sysmex and Advia retic counters?: Sysmex - based on flourescent staining.

Advia - based on light scatter.
Which analyzers use electrical impedence for counting?: -Coulter
-Sysmex
-Celldyne
Which parameter is measured identically in all of the analyzers?: Hemoglobin
Which analyzers use cytochemical stain?: -Sysmex - for eos/basos
-Advia - for everything.
Which analyzers use NO cytochemical stain?: Coulter
Cell-dyn
when would you see a dual-population of cells on the RBC histogram?: in iron def. anemia
post-transfusion
a platelet histogram shifting to the right indicates:: platelet clumping and giant platelets.
a RBC histogram that has a high takeoff indicates: Where would nRBCs be?: schistocytes, platelets.

nRBCs are to the right of normal because they are BIGGER.

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