Section 15: Heme Instruments/troubleshooting COPY

Question 1

What methods does the Coulter Principle use?

Answer 1

Impedance or direct current technology

Question 2

What does the Coulter Principle do in terms of cells?

Answer 2

basic principle of counting and sizing particles in two containers separated by a small hole (aperture) and electrodes are on top of each container

Question 3

In the coulter principle, how is resistance measured? What solution is added?

Answer 3

with electrodes connected to a ohmmeter, a saline solution is added

Question 4

In the coulter principle, after cells are added to one side and the spigot is opened what happens?

Answer 4

each time a cell passes through the aperture it displaces a small amount of electrolyte and increases resistance between electrodes

Question 5

If you drain 1mL from the cell side of the container (coulter principle) and count the number of needle flicks, what would you learn?

Answer 5

you would learn the number of cells per mL in suspension

Question 6

What happens if you replace the ohmmeter with a battery oscilloscope in the coulter principle?

Answer 6

each cell through the aperture creates an electrical pulse/spike on the oscilloscope and the height of the spike is proportional to cell sizes

Question 7

What is a threshold?

Answer 7

a set size limit used to choose a pulse size

Question 8

what is a channel?

Answer 8

area between thresholds, can be used to sort a population into many subgroups by size

Question 9

what are some notes about the aperture impedance system?

Answer 9

eliminates recirculation of cells
cells pushed away from critical (counting) zone by diluent
more accurate counts

Question 10

what is coincidence correction?

Answer 10

provides accurate histograms and reliable cell sizing for RBC and PLT indices

Question 11

what kind of counting does the aperture impedance system use?

Answer 11

triplicate counting, ensures precision and reduces repeats

Question 12

Describe the RBC histogram pictured

Answer 12

normal :)

Question 13

Describe the RBC histogram(s) pictured

Answer 13

top left: cold aggultination
top right: macrocytosis, target cells..etc
bottom left: rbc fragments, microcytes
bottom right: DI rbcs, transfusion (dimorphic)

Question 14

What things are measured with RBC grading?

Answer 14

accurate MCV, RDW
detects DI populations
Micro rbc/fragments
agglutination

Question 15

Describe the PLT histogram

Answer 15

normal

Question 16

What does PLT curve fitting do?

Answer 16

allows more accurate counts when PLT are larger than 20 fL

Question 17

PLT counting and sizing: coulter impedance counting has what kind of curve fitting? what does it do?

Answer 17

has patented curve fitting and is a process that is used in conjugation w/ wbc histogram review for plt clumps and giant plt flags

Question 18

Describe what is happening in the plt histograms

Answer 18

top: giant plts
bottom: small plts

Question 19

Coulter wbc histogram: what cells correspond to the REL NO.?

Answer 19

Lymphs: 50-90fl
baso
Monos: 90-160fl
eos
Neuts: 160-450fl

Question 20

How many fL are lymphs, Monos and Neuts each?

Answer 20

Lymphs - 50-90fl
Monos - 90 - 160 fl
Neuts - 160 - 450fl

Question 21

Describe the WBC histograms present

Answer 21

top left: granulocytes w varied sizes, immature neuts
top mid: lymphocytosis
top right: varient lymphs/blasts
bottom left: imm neuts
bottom mid: eos
bottom right: varient lymphs/blasts

Question 22

Near native wbc analysis

Answer 22

rbc removed from dilution using lytic process; second agent prevents alteration of white cells

Question 23

notes about hydrodynamically focused flowcell

Answer 23

laminar flow ensures single file cell passage
coincidence effects are minimal

Question 24

What is flow cytometry?

Answer 24

technique for counting/exam/sorting particles suspended in a fluid stream. Allows multiparametric analysis of characteristics of single cells

Question 25

What are some factors of biophysical flow cytometry?

Answer 25

cells are hydrodynamically focused, diluted blood is injected into "sheath" of buffered saline which forces cellls past detector

Question 26

VCS technology uses what three main principles?

Answer 26

volume, light scatter and conductivity

Question 27

What are some main principles used by the 3-D VCS Scatterplot?

Answer 27

nuc shape and comp granules cytoplasm cell size

Question 28

Define the following terms in regards to coulter VCS technology: Volume Conductivity light scatter:

Answer 28

volume = size conductivity = internal comp light scatter = cell shape/surface

Question 29

how is total cell volume measured?

Answer 29

measured using reference method of direct current impedance and is unaffected by cell orientation

Question 30

Conductivity: how is internal cell structures measured?

Answer 30

measured via radiographic imaging (similar to ultrasound) proprietary technology

Question 31

how is light scatter/cell surface granularity measured?

Answer 31

measured using a broad range of angles. over 60 angles of light scatter are analyzed

Question 32

3-D cellular analysis - VCS measures what three things in the 3D field?

Answer 32

Volume, conductivity, light scatter are all directly measured

Question 33

Describe the data plot

Answer 33

normal

Question 34

Sysmex direct current w/ hydrodynamic focus uses what and measures what?

Answer 34

uses fluorescent flow cytometry - nuc acid and cytoplasmic organelles measures fluorescnes and side angle light scatters

Question 35

Sysmex WBC measures what?

Answer 35

measures the forwards scatter, side scatter and side fluorescenes of wbc populations

Question 36

sysmex WBC placement in the scatter is based on what two components?

Answer 36

size (forwards scatter) and internal comp (side)

Question 37

sysmex RBC counting method: RBC and HCT are measured based on what technology?

Answer 37

impedence technology (DC) HCT measured based on volume of rbc determined by DC detection

Question 38

sysmex hemoglobin measurement is used with?

Answer 38

utilizing Sodium Lauryl Sulfate (SLS) has no cyanide and minimal interface in lipemic samples or w ab proteins

Question 39

What are the three steps in SLS measurement?

Answer 39

1.) denaturation of globin molecule 2.) oxidation of heme molecule 3.) conversion of SLS-hgb

Question 40

Siemens healthcare: Advia: what are the three main points?

Answer 40

flow cytometry based light scatter MPO

Question 41

Abbott Cell-DYN sapphire: what are the 4 main focusing points?

Answer 41

optical light scatter fluorescence impedance MAPSS