and the severity of the bleeding is proportional to the degree
of deficiency. In order to treat the hemorrhagic condition,
it is important to identify and quantify the deficient factor.
Fibroscreen reagent is one such test reagent, which can
identify the deficiency of factor I (fibrinogen). The reagent
is used as a source of thrombin to determine the qualitative
Fibroscreen reagent is a lyophilized preparation of bovine
thrombin of 50 NIH/mL. Reconstitute with 1 mL of distilled
water; wait for 5 minutes, do not shake and mix gently by
swirling till the solution attains homogeneity. Further keep
aside for 10 minutes to attain equilibrium. Gently swirl the
vial while drawing the reagent for use. Once reconstituted
it is ready to use reagent for the thrombin time test.
1. Store the unopened reagent vials at 2–8°C. Do not
2. The shelf-life of the reagent is as per the expiry date
mentioned on the reagent vial label and carton label.
3. Once reconstituted the Fibroscreen reagent is stable
for 6 days when stored at 2–8°C and for 4 hours
at room temperature (20–25°C), provided it is not
contaminated. Extreme care has to be taken to maintain
aseptic precautions while reconstituting, retrieving
and handling reagents to prevent contamination. The
Fibroscreen reagent vial must be replaced at 2–8°C
immediately upon retrieving the reagent for the day’s
When a known quality and concentration of Fibroscreen
reagent is added to citrated plasma, by observing the time
required for clot formation and the quality of clot formed,
a qualitative estimation of fibrinogen in the sample can be
1. In vitro diagnostic reagent for laboratory and professional use. Not for medicinal use.
2. The reagent contains 0.1% sodium azide as preservative.
3. Fibroscreen thrombin reagent is not from a human
source, hence contamination due to HBsAg, HIV and
4. It is very important that absolutely clean and dry
micropipettes be used to aspirate and dispense the
5. Avoid exposure of the reagent to elevated temperatures,
direct light and contamination. Immediately replace
cap after use and store at recommended temperature.
A known normal control should be run in parallel with
each batch of tests. This control may be Tulip plasma
coagulation control Plasmatrol-I or freshly drawn normal
No special preparation of the patient is required prior to
sample collection by approved techniques. Withdraw
blood without undue venous stasis and without frothing
into a plastic syringe fitted with a short needle of 19 to
20 SWG. The venipuncture must be a ‘clean’ one and,
if there is any difficulty, take a new syringe and needle
and try another vein. Transfer the blood into tubes, after
detaching the needle from the syringe. Mix nine parts of
freshly collected blood with one part of sodium citrate
(0.109-M mol/L, 3.2%). Centrifuge immediately for fifteen
minutes at 3000 rpm (approximately 2000 g) and transfer
the plasma into a clean test tube. Plasma must be tested
10 ×75 mm glass test tubes, 0.2 mL precision pipettes, stopwatch, distilled water, fresh plasma.
Bring all the reagents and samples to room temperature
Testing should be done in duplicate at room temperature
1. To a clean and dry 10 × 75 mm test tube add 0.2 mL
of plasma to be tested and 0.2 mL of the reconstituted
2. Start a stopwatch simultaneously with the addition of
3. Shake the tube gently to mix the contents and then tilt
4. Note the time at the first appearance of the clot and for
the remaining portion of 60 seconds for consistency
and character of the clot formed.
Normal plasma begins to show clot formation within 15
seconds after Fibroscreen reagent has been added. Because
time of clot formation may be influenced by additional factors
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