Basic Investigations in Haematology Lecture 5 - Automated Haematology Analyzers Flashcards

75 fill-in-the-blank flashcards covering key principles, parameters, histograms, scattergrams and flagging systems discussed in the automated haematology analyzers lecture.

Automation in haematology provides many advantages, but one major disadvantage is __.

flagging

Current haematology analysers combine light scatter, electrical impedance, fluorescence, light absorption, and __ for cell analysis.

electrical conductivity systems

Fluorescence-activated cell sorting is commonly abbreviated as __.

FACS

In flow cytometry, forward scatter mainly correlates with cell __.

size

In flow cytometry, side scatter reflects the __ of intracellular structures.

complexity

On a WDF scattergram, fluorescence staining intensity is represented by the __ axis.

SFL (Side Fluorescence Light)

A standard CBC evaluates red blood cells, white blood cells, and __.

platelets

The red cell indices are calculated from RBC count, haemoglobin, and __.

haematocrit

MCV stands for __.

mean corpuscular volume

The reference range for RDW-SD is __ fL.

37–46

The reference range for RDW-CV is __ %.

11–16

An increased RDW is a laboratory marker of __.

anisocytosis

RDW-CV is especially useful in diagnosing __.

hereditary spherocytosis

An RBC histogram ‘RL’ flag may be caused by giant platelets, microerythrocytes, RBC fragments, or __.

platelet clumps

An RBC histogram ‘RU’ flag can result from __ agglutination.

cold (RBC)

When cold agglutinates produce an ‘RU’ flag, warm the sample to __ °C.

37

A ‘DW’ flag appears when the RBC histogram curve crosses __.

neither the LD nor UD lines

MPV is an abbreviation for __.

mean platelet volume

The reference range for MPV is __ fL.

8–12

MPV (fL) can be calculated as __ divided by PLT (×10³/µL).

PCT (%)

P-LCR represents the __ of large platelets.

ratio

The reference range for P-LCR is __ %.

15–35

A ‘PL’ flag on the PLT histogram may be caused by high blank value, cell fragments, bacteria, or __ reagents.

contaminated

A ‘PU’ flag on the PLT histogram can be due to __ incompatibility.

EDTA

Multiple peaks (‘MP’ flag) in a PLT histogram may occur during recovery after __.

chemotherapy

On the WBC histogram, LD cannot be set lower than __ fL.

30

The WBC histogram flag ‘WL’ can be triggered by __-resistant RBC.

lyse

To correct a ‘WU’ flag, a useful technique is __ of the sample.

predilution

Flags F1, F2, and F3 indicate an __ differential.

abnormal

Corrected WBC count = WBC × 100 / (NRBC + __).

100

During treatment of iron-deficiency anaemia, a mixed population flag represents microcytes and __.

normocytes

Macrocytic anaemia is characterised by an increased __ value.

MCV

The normal adult WBC count range is __ ×10³/µL.

4–10

The normal adult platelet count range is __ ×10³/µL.

150–400

Normal haemoglobin for adult men is __ g/dL.

14–18

The reference range for MCV is __ fL.

85–95

Using fluorescent antibodies, FACS can analyse a nearly limitless number of different __ at once.

parameters

In FACS, each droplet receives an __ charge before sorting.

electrical

Charged droplets are deflected into tubes by __ fields.

electrostatic

Scattergrams are displayed in two dimensions, but the data originate from measurements in __ dimensions.

three

For CBC discrete mode, the analyser plots __ versus SSC.

FSC (Forward Scatter)

Using SFL in WDF analysis helps reduce analytical __.

interferences

One of the six SAFLAS cloud descriptors is __, indicating direction of the longitudinal axis.

angle

Linear discriminant analysis seeks to maximise deviation __ groups.

between

In the Q-Flag system, values above __ are shown in red.

100

The analyzer flag “Blasts/Abn Lympho?” indicates possible presence of __ lymphoid cells.

abnormal

The suspect flag “__?” is produced when immature granulocytes are present.

Left Shift

On a WDF scattergram, immature granulocytes cluster between monocyte and __ regions.

neutrophil

RET-He represents the haemoglobin content of __.

reticulocytes

Early monitoring of anaemia therapy can be assisted by the parameter __.

RET-He

The reference range for PDW is __ fL.

9–14

An increased PDW may signal platelet clumps, microerythrocytes, or cell __.

fragments

EDTA-induced platelet clumping can yield falsely __ platelet counts.

low

To avoid EDTA-induced clumping, recollect the sample in a __ tube.

citrate

A high blank value should be investigated by performing a(n) __ check.

background (blank)

A WBC abnormal scattergram appears when 5-part differential data cannot be __.

calculated

On the WDF scattergram, eosinophils form a separate cluster because of their high __ scatter.

SSC (Side Scattered Light)

In CBC discrete mode, WBC are separated from __ using a minimal number of dot searching method.

debris

NRBC presence requires a WBC __ to obtain accurate counts.

correction

A high number of particles before the WBC LD triggers the flag __.

AG

Cold RBC agglutination can falsely lower RBC and affect HCT, MCV, MCH, and __.

MCHC

If the PLT histogram curve does not match the 20 % line twice, PDW and __ cannot be calculated.

P-LCR

In WDF flagging, the ‘shape score’ is used to evaluate lymphocyte and __ cloud morphology.

monocyte

Monocytes and lymphocytes are separated on the basis of cell complexity and __ intensity.

fluorescence staining

In the RET channel, very small dots on the scattergram represent __.

platelets (PLT-O)

IRF is derived from LFR, MFR, and HFR percentages on the __ scattergram.

RET

Flow cytometry can analyse up to __ of particles per second.

thousands

In FACS, data for each cell include FSC, SSC, and __ signals.

fluorescence

Charged droplets in FACS are deflected into collection tubes by __.

electromagnets

All widely used automated haematology instruments are highly specialised __.

flow cytometers

PDW stands for __.

platelet distribution width

An increased P-LCR may indicate giant platelets, microerythrocytes, or platelet __.

clumps

The suspect flag ‘Left Shift?’ indicates increased numbers of __ granulocytes.

immature

On the analyser, ‘IG’ is the abbreviation for __.

immature granulocytes

The normal haematocrit range for adult men is __ %.

43–49

After an RBC transfusion, the RBC histogram may show a __ distribution due to donor and recipient cells.

bimodal