Dr. Sadaf Khan discusses automated cell counters and complete blood count (CBC) analysis. Automated cell counters have advanced from semi-automated in the 1950s to fully automated today. CBC analysis involves counting red blood cells, white blood cells, platelets, and other parameters. Automated cell counters use various principles including impedance, light scattering, and flow cytometry to analyze CBC samples and provide accurate and efficient results. Proper sample handling and quality control are important to obtain reliable results from automated cell counters.
3. CBC specimens must be checked for
-clots (visually, by applicator sticks, or by automated
analyzer histogram inspection or flags),
-significant in-vitro haemolysis and
-interfering lipaemia
CBC processing, either automated or manual, should be
done within 8 hours but in no case later than 24 hours of
sample collection
Blood samples must be adequately mixed before analysis.
5.
AUTOMATED CELL COUNTERS
ADVANTAGES DISADVANTAGES
• Speed
• Number of samples
• Increased reliability, accuracy
and precision
• Multiple tests simultaneously
• Reduced labor requirements
• Cost
• Spurious results
• Interfering factors
• Red cell morphology
• Less efficient in detecting
atypical cells
• Flagged samples need review
6.
CBC: WBC, RBC, Hgb, PLT, RBC indices,
RDW-SD( LH 780)
WBC Differential: can be
• 3 part
• 5 part
• 6 part
Nucleated red cell count
cWBC count(LH 750)
Reticulocyte count
Body fluid counts
PARAMETERS
7. • Number of pulses = number of cells counted
Height of pulse volume of cell
SAMPLE
DILUTED
WITH
BUFFERED
SALINE
CELL
DRAWN
THROUGH
APERTURE
CHANGE IN
RESISTANCE
DETECTION
OF PULSE
IMPEDANCE- COULTER PRINCIPLE
16.
Non central cell flow can give rise to inaccurate cell
size data.
Does not affect the actual count
Corrected by – PULSE EDITING
HYDRODYNAMIC FOCUSSING
NON AXIAL FLOW
17.
18. Modes-
• automatic- 350 micro
• manual – 200micro
Closed tube system
Requirements-
• Bloods collected in EDTA
• Bar code labels
• Slides and cassettes for LH SlideMaker
• Required reagents and diluents
• LH Workstation with HELP
• LH 780 with LH SlideMaker and LH SlideStainer
BECKMAN COULTER LH 780
21. Coulter RBC histogram
It is a graphic representation of blood cells
Produced from thousands / millions of signals generated by the cells
passing through detector where they are differentiated by their size and
frequency of occurrence in the population
The Size Distribution Curve should always start on the base line and fall
between the lower and the upper discriminator.
Main RBC
population
RBC doublets
22. RBC FLAGS
SUSPECT DEFINITIVE
• nRBCs
• Fragmented RBCs
• H and H error
• Aged sample
• Anemia
• Anisocytosis
• Microcytes
• Macrocytes
23. PLT histogram and curve fitting
Typical platelet histograms are log normal and have two
curves for accurate count:
A smooth curve from 2 to 20 fL.
A fitted curve from 0 to 70 fL
The Platelet count is derived from the number of cells under
the fitted curve from 0 fl extending up to 70 fl
Fitted Curve extend up to 70 fl to report very large PLT count
Raw data
30. ORBITAL MIXING
CHAMBER:
Blood from the loop on
the center section of the
BSV is pushed to the
mixing chamber by the
Erythrolyse and mixed.
Erythrolyse lyses the
RBC’s by creating a
hypotonic environment.
Stabilise is added at the
right time and mixed to
stop the action of the
Erythrolyse.
WBC’s are left in their “near
native state”.
SAMPLE
PRESSURE
SHEATH
TANK
VENTED
WASTE
SHEATH
FLUID
SAMPLE
FLOW
CELL
PREPARED
7135-035
31. Sample Flow
Sample is pushed to Flow
Cell.
Upper & lower sheath in
ports supply flow cell with
Sheath Fluid from Sheath
Tank
The sample stream is
hydrodynamically focused.
Sheath surrounds sample but
does not mix.
Sample Pressure > Sheath
Pressure
Cells are analyzed one at a
time as they pass through
the center of the flow cell.
All three VCS technologies
are applied simultaneously
32. WBC with all three
technologies applied
simultaneously:
Volume- Coulter Principle
using direct current.
Conductivity- high
frequency current.
Light Scatter- Laser light.
33. WBC interacting
with all three
technologies to
provide VCS
characteristics for
Diff analysis.
Contour gating
Coulter Principle
Direct
Current
Total Cell
Volume
Total Cell
Volume
Conductivity Principle
High
Frequency
Current
Nucleus,
Cytoplasm,
Etc.
Granularity
Light Scatter Principle
Laser
Shape &
Surface
Characteristics
35. Forward-angle light scatter (FALS)
Illuminating beam that has been bent to a small
angle from direction of the original beam .It
measures size or volume of cells
36. Side scatter (SSC)
The illuminating beam that is scattered by particle to
an angle of 90* from the illuminating beam.
This depends on cell's surface texture and internal
structure as well as to its size and shape and
granularity.
It is sometimes referred to as a granularity signalor
an orthogonal light scatter signal.
40. Immature HLR .
Retic = Total Retic #
Fraction
High light
Scatter Retics
(HLR)
RBCs
Platelets
WBCs &
NRBCs
Retics
RETICULOCYTE
Flow cytometric analysis using VCS
41. ERRORS
FLUIDICS
• Clean the
vacuum
trap
• Check tubing
connections
and routing
for leaks or
disconnects
REAGENTS
• High
background
counts
-contaminated
-clean spills
and leaks
-thaw frozen
reagents
TRANSPORT
• Debris on
cassette or
underside of
rockerbed
VLS
VLS Diluent
• Carryover
• Insufficient
rinsing of
vent line
• No air in
vent line
• Automatic
mode
disabled
42. ASPIRATION
C
CARRYOVER
• Backwash-
• diluent
N
NO BLOOD
• Short sample
or clot in tube
• Obstruction
in the aspiration
pathway
• Diluted blood
• Low Hgb
(approx. ≤ 4 g/L)
B
BUBBLE
• Short sample,
clot or bubble
• Obstruction in
the aspiration
pathway
• Bubble
P
PARTIAL
• Short sample
or clot in tube
• Obstruction in
the aspiration
pathway
• BSV did not
rotate fully
• Blood detectors
turned OFF
• Diff or Retic
Sample Valves
did not move
correctly
TROUBLESHOOT
• Clots and sufficient sample volume
• Repeat in manual mode
• Clean needle, remove and replace if necessary
• Inspect/Clean BSV ensure it is not leaking
• Partial clogging in flow cell can be corrected
by LATRON CONTROL.
43. Beckman Coulter Unicel DxH 800
VCSn module- DLC
and nRBCs
Multitransducer
module for flow cell
analysis
Light scatter
-LMALS and UMALS: cells
granularity and topography
-AL2 : cellular transparency
-LALS: cellular complexity
index
NRBCs- DxH diluent+
DxH cell lyse
51.
First hematology instruments to introduce extended
RBC and reticulocyte parameters
Delta neutrophil index-
prognostic indicator
early marker of sepsis
CSF analysis
SIEMENS HEALTHCARE ADVIA
52.
Beckman coulter SYNCHRON LX Ri725
It can perform 146 chemistry and immuno assay tests
including basic critical care, metabolic ,cardiac,
Thyroid ,Reproductive, tumour markers .
Recent advances
53.
5million sample analysis /year
100 parameters in patient samples, including blood, urine
and CSF
They are linked to Novel laboratory information system
MOLIS (Sysmex)
OLYMPUS OLA2500