Unit 3.6 PRINCIPLES OF AUTOMATION IN HEMATOLOGY

Question 1

refers to the use of laboratory instruments and processing equipment to perform clinical laboratory assays with only minimal involvement of the medical technologist

Answer 1

Automation

Question 2

2 Classic automated methods for counting cells

Question 3

Coulter Counter

Answer 3

Electronic Impedance/Resistance

Question 4

Technicon Autoanalyzer; Ortho Diagnostic; Fisher Autocytometer

Answer 4

Optical Detection/Light Scattering

Question 5

The Basic Components Common to Most Hematology Analyzers

Question 6

includes the aspirating unit, dispensers, dilutors, mixing chambers, aperture baths, and/or flow cells, and hemoglobinometer

Answer 6

Hydraulics

Question 7

Vacuum and pressures for operating values and moving the sample through the system

Answer 7

Pneumatics

Question 8

Electronic analyzers and computing circuitry for processing data

Answer 8

Electrical systems

Question 9

Blood is diluted in an isotonic solution and drawn through an aperture.

Answer 9

ELECTRIC IMPEDANCE

Question 10

Since cells are nonconductive, the passage of cell through the aperture increases the resistance (impedance) of the electrical path between 2 electrodes that are located on each side of the aperture.

Answer 10

ELECTRIC IMPEDANCE

Question 11

Changes in electrical resistance are counted as

Answer 11

voltage pulses.

Question 12

Number of Voltage pulses is directly proportional to the

Answer 12

number of cells/cell cou nt.

Question 13

Amplitude/height/size of the pulse is directly proportional to the

Answer 13

volume of the cell

Question 14

a diluted blood specimen passes through a steady stream through which a beam of LASER light is focused.

Answer 14

LIGHT SCATTERING

Question 15

As each cell passes through the s ensing zone, it scatters light. Scattered light is converted into an electrical pulse.

Answer 15

LIGHT SCATTERING

Question 16

LIGHT SCATTERING

Number of pulses is directly proportional to

Answer 16

cell count

Question 17

LIGHT SCATTERING

Patterns of scatter are measured at various angles to obtain information on the

Answer 17

cell structure.

Question 18

Dilutions :
WBC= (?) (usual dilution, but may vary among manufacturers)
RBC=

Answer 18

1:500
1:50,000

Question 19

graphic representation of cell size versus cell frequency

Answer 19

HISTOGRAMS:

Question 20

produced in RBC, WBC & platelet measurements

Answer 20

HISTOGRAMS:

Question 21

Derived from the histogram are

Answer 21

blood Indices as well as WBC differential

Question 22

RBC histogram:

Answer 22

36 360 fL

Question 23

It IS where MCV & RDW are derived

Answer 23

RBC Histogram

Question 24

Histogram appears (?) when cell population is (?) if there is more variation in the size of the cell

Answer 24

SYMMETRICAL/Gaussian shape

homogenous WIDER or FLATTENED shape

Question 25

Platelet histogram:

Answer 25

2 - 20 fL

Question 26

Where MPV & PDW are derived

Answer 26

PLATELET Histogram

Question 27

(used in the 3-parameter Differential count)

Answer 27

WBC Histogram

Question 28

WBC Populations on the histogram 35 - 90 fL: 90 - 160 fL: 160 - 450 fL:

Answer 28

Lymphocytes Mononuclears (Mid cells) - (Monocytes, Promyelocytes, Myelocytes, Blasts) Granulocytes - (Mature WBC, Blasts, Metamyelocyte, Bands)

Question 29

a visual display of 2-cell characteristics such as internal cell complexity and relative size

Answer 29

SCATTERGRAM / CYTOGRAM / DOT PLOTS

Question 30

It is used in the 5-part automated differential.

Answer 30

SCATTERGRAM / CYTOGRAM / DOT PLOTS

Question 31

SCATTERGRAM / CYTOGRAM / DOT PLOTS Cytochemical stains Peroxidase: Alcian blue/Toluidine blue: Lipase/Esterase:

Answer 31

PMN & other cells basophil monocytes

Question 32

What are the indications of histograms with left elevation? with right elevation?

Question 33

What are the bases of separation of cells in a scattergram? _________________________ _________________________

Question 34

WBCs are differentiated into 5 traditional categories

Question 35

Cyanmethemoglobin principle

Answer 35

HEMOGLOBIN

Question 36

HEMOGLOBIN At what wavelength? ________

Question 37

Indirect method (calculated)

Answer 37

HEMATOCRIT

Question 38

HEMATOCRIT What is the formula? ________

Question 39

MCH & MCHC are calculated from measure & derived values RDW

Answer 39

INDICES

Question 40

From where is RDW derived? ________

Answer 40

INDICES

Question 41

Aperture plugs

Answer 41

Causes of POSITIVE errors

Question 42

Extraneous electrical pulses (improperly grounded or shielded equipment)

Answer 42

Causes of POSITIVE errors

Question 43

Bubbles in the sample (vigorous mixing)

Answer 43

Causes of POSITIVE errors

Question 44

Improper setting of aperture current or threshold

Answer 44

Causes of POSITIVE errors

Question 45

Agglutinated red cells or platelets

Answer 45

Causes of POSITIVE errors

Question 46

Excessive lysing of RBCs

Answer 46

Causes of NEGATIVE errors

Question 47

Improper setting of aperture current or threshold

Answer 47

Causes of NEGATIVE errors

Question 48

Agglutination of RBCs, WBCs or platelets

Answer 48

Causes of NEGATIVE errors

Question 49

a quality control check in which the averages of the MCV, MCH, MCHC are tracked for batches of 20 patients

Answer 49

XB

Question 50

Patients test results are compared to his previous results

Answer 50

Delta Checks

Question 51

: suggest cells types/abnormalities

Answer 51

Flags

Question 52

indicate investigation before final reporting.

Answer 52

Flags

Question 53

What are the causes of falsely increases and falsely decreased automated cell counts? – RBC, WBC & Platelets (Henry's Clinical Diagnosis and Management by Laboratory Methods)

Question 54

What conditions may affect automated hemoglobin measurement? Explain each

Question 55

(What are the indications for)/When should we perform a manual peripheral blood smear review?