Automated Counters

Front 1

What machine measures MCV and calculates the hematocrit?

Back 1

Sysmex.

Front 2

What machine measures Hct and calculates the MCV?

Back 2

Coulter.

Front 3

which analyzer does not use light scatter?

Back 3

Sysmex.

Front 4

Which analyzer has to manipulate eos/basos to differentiate them?

Back 4

sysmex.

Front 5

which analyzer has von behren's plates instead of sweepflow?

Back 5

cell dyn

Front 6

what is the principle of the cell dyn?

Back 6

cells are passed between plates with apertures of different size; prefer to flow through the larger, and get counted.

Front 7

which analyzer uses DC/RF for volume determination and differentiation?

Back 7

sysmex

Front 8

is there a chance of coincidence loss on the cell dyne?

Back 8

yes; to correct, use pulse editing.

Front 9

which analyzers seperate a section of cells for hemoglobin via cyanmethemoglobin colorimetry?

Back 9

all of them

Front 10

what two ways are white cells counted and differentiated on the cell dyne? (2 acronyms)

Back 10

WIC - white cell impedence cnt.
WOC - white cell optical count.

the first uses impedence, the second uses light scatter.

Front 11

what is different between the sysmex 9000 and 3000?

Back 11

9000 uses DC/RF; the 3000 does not use RF for differentiation, but instead light scattering.

Front 12

what is cell dyn's claim to faim?

Back 12

WIC and WOC - two counts based on impedence, and light scatter.

Front 13

what angles does the cell dyn scatter light?

Back 13

FAS - forward
orthogonal - 90, right angle
depolarized
10 - narrow angle

Front 14

On Celldyn, what does the FAS measurement tell you?
-90 right angle?
-90 depolarized?
-10?

Back 14

FAS = the size of cell
right angle = granularity
depolarized = eosinophils
10 = n:c ratio - nucleus density

Front 15

what type of sheath fluid is in the cell-dyn?

Back 15

weak salt that pulls hemoglobin out of cells so there's no interference.

Front 16

what type of light source is used in the cell-dyn?

Back 16

polarized helium argon laser.

Front 17

what is the acronym for the special light scattering used in the cell dyn?

Back 17

MAPSS - multi angle polarized scatter seperation

Front 18

what is list-mode analysis?

Back 18

whatever electrical information is gathered from each cell is given in a direct plot, not a box scatterplot.

Front 19

which analyzer shows exactly whre basophiles are in the electrical information?

Back 19

cell-dyn, don't have to rotate the scattergram to visualize them.

Front 20

what is advia technology based on?

what is it NOT based on?

Back 20

light scattering
cytochemical staining

not on electrical impedance.

Front 21

is advia good?
what is it good at?

Back 21

no; it's unwieldy and difficult to interpret;
give the best RBC information

Front 22

What do cold agglutinins do to an analysis?

Back 22

cause RBCs to clump and give an abnormal RBC count;
Hct will be wrong, but Hgb will be normal because cells are lysed.

Front 23

how do you fix cold agglutinins?

Back 23

warming the sample and rerun it.

Front 24

What causes a high take-off?

Back 24

anything smaller than a lymph.

Front 25

specific things that cause high takeoff?

Back 25

-Platelet clumps
-Fibrin strands
-nRBC
-Cryoglobulins

Front 26

if you have nRBCs, what do they do to the analysis, and how do you correct it?

Back 26

will cause a high-take-off. do a manual diff and correct for the nRBCs.

Front 27

if you have platelet clumps, how do you correct?

Back 27

do a manual platelet count.

Front 28

when the WBC count is over 90000 cells/uL, what happens to the analysis?
How do you correct it?

Back 28

invalidate the WBC count;
to correct, dilute the sample and rerun it.

Front 29

if the WBC count is greater than 2% of the RBCs, what does this mean?

Back 29

You must correct the RBC: subtract two percent of the RBC from the old RBC count for a new one.

Front 30

What are the effects of a high WBC count?

Back 30

-falsely elevated HgB (cloudy)
-incorrect RBC and MCV
-Hct must be spun, not calculated.

Front 31

what stain is used in normal retic counts?

Back 31

new methylene blue

Front 32

what occurs in an automated retic counter? (process)

Back 32

1. cells are stained/incubated.
2. in weak H2SO4, cells lyse, Hgb escapes, and a ghost with precipitated RNA remains.

Front 33

What are the 2 major types of automated retic counters?

Back 33

R-3000 by Sysmex;

Advia Retic counter

Front 34

What type of dye does the sysmex use?

Back 34

Auromine-O flourescent dye.

Front 35

what type of dye does the Advia retic counter use?

Back 35

Oxazine 750

Front 36

what type of technology does the Advia retic counter use?

Back 36

Light scattering - at three angles.

Front 37

What does IRF refer to?

Back 37

the advia's zones for high and medium staining retics; was used as an indicator of whether a bone marrow graft was successful.

Front 38

what's the difference btwn the Sysmex and Advia retic counters?

Back 38

Sysmex - based on flourescent staining.

Advia - based on light scatter.

Front 39

Which analyzers use electrical impedence for counting?

Back 39

-Coulter
-Sysmex
-Celldyne

Front 40

Which parameter is measured identically in all of the analyzers?

Back 40

Hemoglobin

Front 41

Which analyzers use cytochemical stain?

Back 41

-Sysmex - for eos/basos
-Advia - for everything.

Front 42

Which analyzers use NO cytochemical stain?

Back 42

Coulter
Cell-dyn

Front 43

when would you see a dual-population of cells on the RBC histogram?

Back 43

in iron def. anemia
post-transfusion

Front 44

a platelet histogram shifting to the right indicates:

Back 44

platelet clumping and giant platelets.

Front 45

a RBC histogram that has a high takeoff indicates:

Where would nRBCs be?

Back 45

schistocytes, platelets.

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