I. Complete Blood count
The examination in whole blood is used mainly for diagnosis and management of complete blood count.
PRINCIPLE OF EXAMINATION
Blood sample is aspirated, measured to a predetermined volume, diluted at the specified ratio,and then fed into each transducer. The transducer chamber has a minute hole called the aperture. On both side of the aperture, there are the electrodes between which flows direct current. Blood cells suspended in the diluted sample pass through the aperture, causing direct current resistance to change between the electrodes. As direct current resistance changes, the blood cell size is detected as electrical pulses. All counts are derived by Electrical Impedance method and Hemoglobin by Non cyanide hemoglobin analysis method
Blood cell count is calculated by counting the pulses, and a histogram of blood cell sizes is plotted by determining the pulses sizes. Also, analyzing a histogram makes it possible to obtain various analysis data.
Differential WBC count done by differentiating lysing action followed by generation of electronic impulses.
PRINCIPLE OF HORIBA YUMIZEN H500& PENTRA XLR
Multi distribution sampling system[MDSS]
Specimen distribution in the chamber is carried out in a tangential flow of reagent which allows perfect mixing of the dilution and avoids any viscosity problems.
LMNE Matrix count: differential count in the flowcell is based on three essential principles:
1. The double hydrodynamic sleeving System “DHSS” which allows a linear flow of the cells through the light path.
2. The cell volume which is measured by electrical current.
3. The measurement of transmitted light at a 0ºangle which allows a measured response according to the internal structure of each cell and its absorbance, as unabsorbed light passes through the spaces in the nuclear material of each cell. This is known as diffused light.
4. 25 µl of whole blood is delivered to the LMNE chamber in a flow of ABX Eosinofix. This reagent lyses the RBC, stabilizes the WBC in their native forms and stains the eosinophil nuclei with a specific coloration.
5. The solution is then stabilized with ABX diluents and transferred to the flow cell. Each cell is measured both in absorbance (cytochemistry) and resistivity (volume).
Parameters RBC, WBCs and platelates are counted by impedence variation measures. Hb is measured by spectrophotometry. Parameters of the WBC differential count obtained by impedence and absorbance.
PERFORMANCE SPECIFICATIONS:
| Specific CV | WBC | RBC | Hb | Hct | PC |
|---|---|---|---|---|---|
| < 5% | < 3% | < 3% | <3% | < 10.0% |
SAMPLE TYPE REQUIRED
Whole blood.
Stored at 2ºC-8ºC after analysis for 24 hrs
PRESERVATIVES NEEDED
Samples are collected in EDTA vaccutainer.
REAGENTS REQUIRED
Lyser, cleaner and Diluent of MICROS 60
CALIBRATION:
Calibration is done by manufacture annually and calibration report is received in the laboratory.
Calibration reports are filed in HI: C\ Records\File\21\Calibration
Records
DETAILED WORK DESK INSTRUCTIONS / PROGRAMMING STEPS:
1] For MICROS 60 cell counter:
START:
SHUTDOWN:-
MAINTENANCE:-
DAILY MAINTENANCE
Go in the main menu, then in service, then in backflush.
2] Horiba Yumizen H500 cell counter:
START:-
SAMPLE PROCESSING:-
If start up is passed we can run the sample.
To Run the Specimen in STAT Mode
1. Press STAT Mode to open the tube holder door.
2. Enter information about the sample.
3.Press Validate in the contextual toolbar.
4. Press Icon (Next analysis) on function toolbar for sampling needle to come out.
5. Gently and thoroughly mix the sample.
6.open the tube and place it below the sampling needle, lift it so that the needle can sample its content.
7. press the manual sampling bar, or press “validate”
8. Remove the tube and put the cap back on once needle has moved up.
SHUTDOWN:- A shutdown cycle has to be from every 24 hrs.
It is highly recommended to perform a shutdown cycle before switching off the instrument.
MAINTENANCE:-
A. Concentration cleaning- to clean the counting chambers and hydraulic parts.
1. Press Concentrated Cleaning.
2. A window informing you to connect Minoclair and press
validate
3. Disconnect the “ABX cleaner luer connected'
4. Connect ABX minoclair luer connector instead
5. Press validate in the contextual toolbar
6. Wait until the cycle is over
- A concentration cleaning cycle takes approx. 10 min.
7. When a window informing you to reconnect a reagent and press
“validate”, disconnect the ABX minoclair luer connecter and
connect ABY Cleaner luerconnector instead
8. Press validate in the contextual toolbar.
9. Startup cycle and an nalysis on a control bood sample
B. Auto clean Cycle
1. Press Autoclean.
2. Wait until the cycle is over
An Autoclean cycle takes about 3 MINUTES
C. Backflush
Clean the counting chamber apertures in case of blockage.
1. Press “ BackFlush RBC/PLT” to backflush the RBC/PLT aperture
2. Wait for the instrument to complete the backflush cycle which takes
about 35 sec.
3. Press ” backflush LMNEB“ to backflush the flowcell
4. Wait for the instrument to complete the backflush cyde, which takes
about 1 min.
D. To prime a reagent
1. Select the reagent you want to prime in Priming/Unpriming area
2. Press prime
3. Wait Until the cycle is over.
E. To Unprime a reagent
1. Disconnect and remove the bottle of reagents You want to unprime.
2. Select the reagents you want to unprime in the Priming /unpriming area
3. Press Unprime
4. Wait until the cycle is over
F. Rinse the system
LMNE flow cells can sometimes be defective due to airbubbles and/or
blockage, this allows to fix both these issues.
1. Press the rinse in the cleaning area
2. Wait for the instrument to complete the rinsing cycle,
which takes approx. 40 sec.
3] ForPentra XLR cell counter:
START:
SAMPLE PROCESSING:
If start up is passed we can run the sample.
To Run the Specimen in STAT Mode
1. Press STAT Mode to open the tube holder door.
2. Enter information about the sample.
3. Select the test to perform by pressing CBC/DIFF/RET.
4. Press CDR if you need a post-dilution on the sample.
5. Select the appropriate dilution ratio for WBC/LMNE and for RBC/PLT/HGB.6. Press Validate in the contextual toolbar.
7. Gently mix the blood specimen.
8. Put the tube in the tube holder and close the door to start sampling.
9. When the door opens, remove the tube from the tube holder and recap it if needed.
To Run the Specimen in Rack Mode
1. Prepare your worklist.
2. If you work with tubes with barcode labels, place the tube on any rack, at any position. Make sure that the barcode label is visible for the internal barcode reader.
3. If you work with tubes with no barcode labels, place the tube on the rack and at the position specified in the worklist.
4. Place the rack on the rack loader.
5. Press Start Rack.
SHUTDOWN:-
SOP TO REPLACE REAGENT:-
1.When a reagent “Low Level” alarm is displayed, press Check.
2. Press the icon of the reagent you need to change
3.Press Edit in the contextual toolbar.
4. Enter the lot number in Lot Nb using the external barcode reader. All the fields are updated and the reagent level is set to an automatic default level. 5. Open the front door and remove the empty bottle from the reagent compartment.
6.Uncap a new reagent bottle. 7. Insert the stopper assembly tube into the new bottle and tighten the stopper assembly to ensure an adequate seal
8.Install the new reagent bottle into the reagent compartment and close the door.
9.Press Validate in the contextual toolbar. The instrument automatically starts priming the reagent.
MAINTENANCE:-
Miniclean: launches a short rinsing cycle of the counting chambers.
Concentrated Cleaning: starts a concentrated cleaning procedure using ABX Minoclair.
AutoClean: launches a cleaning cycle using ABX Cleaner.
Super User Menu: gives access to customer maintenance.
Technician Menu: (reserved to technicians) gives access to advanced maintenance
(Super User is made of three additional menus: ■ Mechanical System which allows the management of mechanical cycles. ■ Hydraulic System which allows the management of hydraulic cycles. ■ Others which facilitates certain maintenance procedures, and allows to force calibration coefficient values and RET parameters)
MAINTENANCE:-
1.Concentration cleaning- to clean the counting chambers and hydraulic parts.
■ Remove the right front cover and the right-hand side panel.
2. Miniclean Cycle
A Miniclean cycle takes about 35 seconds.
3. Autoclean Cycle
An Autoclean cycle takes about 90 seconds.
4. Backflush
Clean the counting chamber apertures in case of blockage.
Only a super user can perform this action.
A backflush cycle takes about 35 seconds.
5. Rinse the Cytometer
Only a super user can perform this action.
The LMNE flow cell can sometimes be defective due to air bubbles and/or blockage. Rinsing the cytometer allows to fix both these issues. To do so, you need to:
A cytometer rinsing cycle takes about 90 seconds.
Cleaning Frequency
| Cycles | < 100 analyses per day | > 100 analyses per day |
|---|---|---|
| Startup | 1 per day | 1 per day |
| Shutdown | 1 per day | 1 per day |
| Autoclean | automatic after a predefined number of analyses | Automatic after a predefined number of analyses |
| Concentrated cleaning | 1 per month | 2 per month |
| Backflush | as needed | as needed |
| Cytometer rinsing | as needed | as needed |
QUALITY CONTROL PROCEDURE
Participate in external quality assessment program ISHTM – AIIMS EQAS programme.
EQAS 3 monthly for Micros 60 (EQ.28 and EQ- 49), Horiba Yumizen H500(EQ- 50) and Pentra XLR (EQ-08)are being done.
Data is maintained inC\Records\File\2\Results of EQA and interlaboratory comparison
Quality control samples are run on the cell counters Micros 60[EQ.28,EQ.49] , Horiba Yumizen H500[EQ. 50] and Pentra XLR[EQ.08].
4.Inter Instrument comparison :
Records of comparative data are maintained in C\Records\File\9\Inter-instrument comparison.
5.Daily one blank run is checked before running the sample for checking the background counts and the data are entered in separate register. C\Records\File\9\Internal Quality Control Records.
| For Micros 60 | |
|---|---|
| Parameter | Background count limits |
| WBC | <0.3 ×103 / cumm |
| RBC | <0.02 ×106 / cumm |
| Hb | <0.1 g/dl |
| Platelet | <10 ×103 / cumm |
| For Horiba Yumizen H500 | |
|---|---|
| Parameter | Background count limits |
| WBC | <0.3×109 cumm |
| RBC | <0.03×106 / cumm |
| Hb | <3 g/dl |
| Platelet | <5×109/ cumm |
| For Pentra XLR | |
|---|---|
| Parameter | Background count limits |
| WBC | 0.3 ×103 / cumm |
| RBC | 0.03 ×106 / cumm |
| Hb | 0.3 g/dl |
| Platelet | 7 ×103 / cumm |
J. INTERFERENCES:
1. Coincidence(i.e. by two cells passing through an orifice simultaneously and being counted as one cellor by a pulse being generated during the electronic dead time of the circuit).
2. By recirculation of cells that have already been counted.
3. By red cell agglutination (which causes a clump of cells to be counted as one cell).
4. By the counting of bubbles, lipid droplets, microorganisms, or extraneous particles as cells.
5. Faulty maintenance may lead to variation in the volume aspirated or the flow rate.
6.pH, temperature, and rate of ionization have to be standardized and remain constant because changes alter the electric field and may lead to artifactual alterations in the size, shape, and stability of the blood cells in the diluent.
7. Diluent must be free of particles and give a background count of less than 50 particles in the measured volume.
CALCULATION OF RESULTS AND UNCERTAINTY:
Not Applicable
BIOLOGICAL REFERENCE INTERVAL
| Parameters | Male | Female |
|---|---|---|
| WBC (103/ mm3) | 3.5- 10 | 3.5- 10 |
| RBC (106/mm3) | 4.5-5.5 | 3.8 -4.8 |
| HB (g/dl) | 14-16 | 12-15 |
| PLT (103/mm3) | 150-400 | 150-400 |
| Neutrophils (%) | 50-80 | 50-80 |
| Lymphocytes (%) | 25-50 | 25-50 |
| Eosinophils (%) | 0-5 | 0-5 |
| Monocytes (%) | 2-10 | 2-10 |
| Basophils (%) | 0-2 | 0-2 |
| HCT (%) | 41-50 | 36-45 |
| MCV (fl) | 80-97 | 80-97 |
| MCH (pg) | 27.0-32.0 | 27.0-32.0 |
| MCHC (g/dl) | 31.5-34.5 | 31.5-34.5 |
| RDW (%) | 11.0-16.0 | 11.0-16.0 |
LINEARITY:
1] For MICROS 60
| Parameter | Range |
|---|---|
| WBC ( 103/mm3) | 0.5-122 |
| RBC ( 106/mm3) | 0.2-8.7 |
| PLT ( 103/mm3) | 10- 4990 |
| HB ( gm/dl) | 2-27 |
| HCT ( %) | 1.8-82.3 |
2] For Horiba Yumizen H500
| Parameter | Linearity limits | Visible range |
|---|---|---|
| WBC ( 109/ L) | 0-300 | 300-6000 |
| RBC ( 1012/L) | 0-8 | 8 - 18 |
| PLT ( 109/L)for Hb ≥15 g/dl | 0- 2500 | 2500-4000 |
| PLT ( 109/L)for Hb<15 g/dl | 0- 4000 | 4000-5000 |
| HB ( gm/dl) | 0-240 | 240-300 |
| HCT ( %) | 0-67 | 67-80 |
3] For Pentra XLR
| Parameter | Linearity limits | Visible range |
|---|---|---|
| WBC ( 103/mm3) | 0-120 | 120-150 |
| RBC ( 106/mm3) | 0-8 | 8 – 18 |
| PLT ( 103/mm3)for Hb ≥2 g/dl | 0- 1900 | 1900-2800 |
| PLT ( 103/mm3) for Hb<2 g/dl and PLT >15×103/mm3 | 0- 2800 | 2800-3200 |
| HB ( gm/dl) | 0-24 | 24-30 |
| HCT ( %) | 0-67 | 67-80 |
REPORTABLE INTERVAL FOR EXAMINATION RESULTS:
1]FOR MICROS 60
| Parameter | Range |
|---|---|
| WBC ( 103/mm3) | 0-150 |
| RBC ( 106/mm3) | 0-18 |
| PLT ( 103/mm3) | 0-6000 |
| HB ( gm/dl) | 0-30 |
| HCT ( %) | 0-90 |
2] For Horiba Yumizen H500
| Parameter | Range |
|---|---|
| WBC ( 103/mm3) | 0-150 |
| RBC ( 106/mm3) | 0-18 |
| PLT ( 103/mm3) | 0- 2800 |
| HB ( gm/dl) | 0-30 |
| HCT ( %) | 0- 80 |
3] For Pentra ES XLR
| Parameter | Range |
|---|---|
| WBC ( 103/mm3) | 0-150 |
| RBC ( 106/mm3) | 0-18 |
| PLT ( 103/mm3) | 0- 2800 |
| HB ( gm/dl) | 0-30 |
| HCT ( %) | 0- 80 |
CRITICAL VALUES:
| Sr | Specific tests/ examination performed | Low | High |
|---|---|---|---|
| 1 | Hemoglobin | <7 g/dl | >20 g/dl |
| 2 | Hematocrit | <20% | >60% |
| 4 | Platelet Count (pediatric) | < 50,000/uL | >10,00,000/uL |
| 5 | Platelet Count (adult) | <50,000/uL | >10,00,000/uL |
| 6 | White blood cells (adult) | <2,000/uL | >30,000/uL |
| 7 | White blood cells (neonate) | <5,000/uL | >30,000/uL |
INTERPRETATION BY THE LABORATORY:
WBC count (approximate), Differential count and platelet must be counterchecked with P/S examination.
POTENTIAL SOURCES OF VARIABILITY:
1. Preanalytical sources of variability: Delayed sample receipt, Leucocytosis, Leukemia, Septicemia, short draw in vacuum tube.
2. Coincidence (i.e. by two cells passing through an orifice simultaneously and being counted as one cellor by a pulse being generated during the electronic dead time of the circuit).
3. By recirculation of cells that have already been counted.
4. by red cell agglutination (which causes a clump of cells to be counted as one cell).
5. By the counting of bubbles, lipid droplets, microorganisms, or extraneous particles as cells.
6. Faulty maintenance may lead to variation in the volume aspirated or the flow rate.
7. pH, temperature, and rate of ionization of have to be standardized and remain constant because changes alter the electric field and may lead to artefactual alterations in the size, shape, and stability of the blood cells in the diluents.