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www.biomaghreb.com
IVD
FT En 33 Date of updating : 10/ 2020 Version B
FIBRINOGEN
CLINICAL SIGNIFICANCE
Fibrinogen (factor I), protein synthesized by the liver, is the substance used in blood to form a clot. Its
determination is used to evaluate abnormal blood clotting. Elevated fibrinogen levels are observed in
acute inflammation and pregnancy; low values are observed in thrombolitic therapy, in hepatic disease,
in the cogenital non fibrinogen in DIC.
PRINCIPLE
In the presence of an excess of thrombin, the clotting time of previously diluted plasma is inversely
proportional to the quantity of plasma fibrinogen.
REAGENT COMPOSITION
Reagent 1 Thrombin Bovin Thrombin
Reagent 2 Diluent Buffer Hepes pH = 7,35
REAGENT PREPARATION
• Reconstitute vial R1 by the volume of preferably sterile distilled water indicated on the label.
• Allow the solution to stabilize for 20 minutes at room temperature (20-25°C).
SAFETY CAUTIONS
Biomaghreb reagents are intended for qualified personnel, for in vitro use (do not pipette with the
mouth).
• Consult the current MSDS available on request or on www.biomaghreb.com;
• Check the integrity of the reagents before use; and
• Disposal of waste: comply with the legislation in force.
For safety reasons, treat any specimen or reagent of biological origin as potentially infectious. Res-
pect the regulation in force
SAMPLE PREPARATION
• Blood is collected by clean venipuncture on liquid trisodium citrate 0.11 M (1 volume of
citrate for 9 volumes of blood).
• Centrifuge for 10 minutes at 4000 rpm (2500g) or allow to settle.
• Perform the determination within 6 hours of specimen collection.
PRESERVATION AND STABILITY
• Before opening: (lyophilisate)
between 2-8°C, until the deadline indicated on the box.
• After opening (Reconstituted) :
8 h at 20 - 25°C;
48 h at 2 - 8°C;
1 month at - 20°C (freeze by small fraction in plastic tube).
PROCEDURE
- Dilute the plasma 1:10 in R2 buffer. This dilution usually results in a coagulation time of 8-25
seconds. (fibrinemia between 1.5 and 4 g/l).
- If the coagulation time is less than 8 seconds, repeat the test with a dilution of 1/20 or possibly 1/30.
In the latter cases, the result obtained will be multiplied by 2 or 3 respectively.
- If the time is longer than 25 seconds, repeat the test on a 1/5 or possibly 1/2 dilution. In the latter
cases, the results obtained are divided by 2 or 5 respectively.
1) MANUAL TECHNIQUE
In a disposable cup of fibrometer at 37°C: Add
Dilute Plasma 200 µl
Maintain 2 min at 37°C
R1 pre incubate at 37° 200 µl
- Simultaneously start the stopwatch;
- Dip the hook regularly in the middle of the tube until a thin fibrin filament appears and note the
coagulation time.
2) TECHNIQUE USING FIBROMETER:
ARM 0,4 ml
In a disposable cup of fibrometer at 37°C: Add
Diluted plasma or capillary blood 200 µl
Incubate 2 min at 37°C
Reagent 1, not incubated, well-mixed 200 µl
Read the clotting time
3) AUTOMATED TECHNIQUE:
Electro magnetic detection
At time of test dilute the plasma in Reagent 2:
Fibrinemia Dilutions Plasma (ml) Reagent R2
Low
Normal
High
1: 5
1:10
1: 20
0.1
0.1
0.1
0.4
0.9
1.9
In a disposable cup. Add:
Diluted plasma or capillary blood 100 µl
Incubate 1 min at 37°C
Reagent 1, not incubated, well-mixed 50 µl
Read the clotting time
Make a double determination by dosage
4) AUTOMATED TECHNIQUE:
Optic detection
At time of test dilute the plasma in Reagent 2.
Fibrinemia Dilutions Plasma (ml) Reagent R2
Low
Normal
High
1:10
1:20
1:40
0.1
0.05
0.05
0.9
0.95
1.95
In a disposable cup. Add:
Diluted plasma or capillary blood 100 µl
Incubate 1 min at 37°C
Reagent 1, not incubated, well-mixed 50 µl
Read the clotting time
Make a double determination by dosage
N.B : To improve the optical detection of the coagulation, it’s necessary to use Kaolin in 10% (re-
constitute the lyophilisate by 2 ml of distilled water for the(
REF
34014 and(
REF
34038) and add 10μl
of kaolin 10% in this vial : it is the working reagent)
*The Kaolin is supplied on demand
RESULTS
• For each clotting time, read off the value of fibrinogen by referring to the correspondence
table specific to each lot or provided in the kit.
• Correction for liquid anticoagulant:
- If the hematocrit is normal, add 20 % to the result
obtained from the table (i. e., multiply the result read on the table by 1.20).
- If the hematocrit is abnormal, multiply the result obtained from the table by the correction factor (C) :
C =
(10-(9 Hte*)
(9-(9 Hte)
*Hte = Hematocrite
ADDITIONAL EQUIPMENT
• Basic equipment of the medical analysis laboratory;
• Automatic or semi-automatic coagulation analyzer.
USUAL VALUES
• Between 2,5 and 4 g/l
REFERENCES
• Claussa : Acta Haematol 17,137 (1957) ;
• Caenj. Larrieu M.j. Sammama M. L’expansion scientifique Paris 1975 ;
• Andrew M.et al. Blood 70, 165 (1987).
IN VITRO DIAGNOSTIC USE
Manufacturer Use by In Vitro Diagnostic Temperature
Limitation
Catalogue number See insert Store away from light Sufcient
for < n > essais
Batch number
