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ABX Micros
4.2.3. Anti-coagulants and their effects (on whole blood)
This is a list of commonly used anti-coagulants used for whole blood collections:
◆Heparin: Causes an increase in cell clumping, (WBC's and PLT's) and modifies cytoplasmic color
with Romanowsky staining (Blue background). An increase in HCT and MCV with high heparin
concentrations > 7.5UL /capillary tube.
◆Trisodium Citrate: Because the anti-coagulant is liquid, it includes a dilution estimated at
10/11 when filling 5ml tubes with whole blood. This anti-coagulant is used in coagulation. It
is sometimes used in hematology when an EDTA - induced Pseudothrombocytopenia is suspected.
◆Acid Citrate Dextrose (ACD) and Citrate Phosphate Dextrose with Adenine (CPDA): The
most commonly used anti-coagulants for cell concentrates (in particular Platelet concentrates)
is normally not used for cell counting. There is no seriously known interference.
Anti-Coagulants used in blood collection may vary in the effects of changing the char-
acteristics of the blood components. Caution is advised when selecting an anti-coagu-
lant for analysis on the ABX Micros 60.
◆EDTA: Amoung the EDTA salts, EDTA K
times NA
Hematology testing Worldwide. Mainly because they have been recommended by ICSH since
1993. The other EDTA salts are acceptable as well. EDTA can include Pseudothrombocytopenia (es-
timated frequency: 1/800) through Platelet clumping.
◆Fluoride: Was used before EDTA replaced it. No side affects as known so far.
4.3. Known Interfering Substances
Verification of any «Abnormal» test result, (including Flagged results or results Outside
their normal range) should be performed using reference methods or other standard lab-
oratory procedures for the conclusive verification of these abnormal results. The section
below starts the list of the known limitations of automated blood cell counters which
use the principle of impedance.
4.3.1. HCT (Hematocrit)
Red Blood cell Agglutination - May produce erroneous HCT and MCV values. Red blood cells agglu-
tination may be detected by observing abnormal MCH and MCHC values, as well as examination of a
stained blood smear in such cases. Manual Laboratory methods may be required to obtain an accu-
rate HCT value.
4.3.2. RBC Red Blood Cells (Erythrocytes)
The Red blood cell dilution contains all the formed elements in the blood: Erythrocytes, Leukocytes,
and Platelets. During the counting of the RBC's, Platelets are below the RBC size minimum threshold,
therefore they are not counted as RBC's.
Leukocytes - (White Blood cells) on the other hand, are included in the RBC count.However,since
the normal ratio between Red blood cells and White blood cells is so extreme, the influence of count-
ing the WBC's during the RBC count is negligible.
High WBC's - In rare cases where the WBC's are extremely high, the RBC count may be corrected,
especially if the RBC count is extremely low in comparison to the high WBC count.
14 - RAB042FEN - User Manual -
60
2
EDTA are used. EDTA K
and EDTA K
2
2
ABX Micros
(USA and Japan), EDTA K
(USA and Europe), and some-
3
are the most frequently used anti-coagulants for
3
60
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