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www.biomaghreb.com
IVD
FT En 26 Date of updating : 10/ 2020 Version B
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
TOTAL PROTEINS
Colorimetric Test (Biuret)
Reagent for the quantitative determination
of total protein in human serum
CLINICAL SIGNIFICANCE
Proteins are macromolecular organic compounds that are widely distributed in the body. They func-
tion as structural elements or transport molecules. Determination of their level is necessary to detect
hyperproteinemia produced by hemoconcentration, dehydration or an increase in the concentration
of specific proteins. Hypo-proteinemia by hemodilution may be due to dysfunction in protein synthe-
sis, excessive losses (hemorrhages) or significant protein catabolism.
PRINCIPLE
Colorimetric method described by Gornall et al (1949). The peptide bonds of proteins react with Cu2+
in alkaline solution to form a blue-violet complex whose absorbance is proportional to the protein
concentration. The Biuret reagent contains sodium potassium tartrate which complexes the copper
ions and maintains their solubility in the alkaline medium.
REAGENT COMPOSITION
Reagent 1
Alkaline
reagent
Potassium-Sodium Tartrate
Sodium hydroxide
Potassium iodide
31, 9 mmol/l
0,6 mol/l
30 mmol/l
Reagent 2
Staining
reagent
Copper Sulphate (Harmful) 0,6 mol/l
Reagent 3
Standard
Bovine Albumin
50 g/l
5 g/dl
SAFETY CAUTIONS
Biomaghreb reagents are intended for use by qualified personnel for in vitro use (do not pipette by
mouth).
• Refer to the current SDS available on request or at www.biomaghreb.com;
• Verify 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.
Respect the legislation in force.
REAGENT PREPARATION
Working Solution :
Add 3 ml of R2 to 1 bottle R1
REF
(27016) and
REF
(27023).
SAMPLE PREPARATION
Heparinized serum or plasma .
PRESERVATION AND STABILITY
• Before opening : The reagents are ready to use, stable up to the expiry date indicated on
the label of the box at 2-8°C;
• After opening : (Working Solution) :
6 months at 2-8°C.
ADDITIONAL EQUIPMENT
• Basic equipment of the medical analysis laboratory ;
• Spectrophotometer or Clinical Biochemistry Analyzer.
QUALITY CONTROL
External quality control program.
It is recommended to control in the following cases:
• At least one test per series.
• Change of reagent bottle.
• After maintenance work on the analyzer.
If a control value is outside the confidence limits, repeat the procedure using the same control.
Use normal and pathological control sera.
CALIBRATION
The standard of the kit (Reagent 3) or any calibrator connected to a method or reference material.
The frequency of calibration depends on analyzer performance and reagent storage conditions.
Recalibration is recommended in the following cases:
1. Changing the reagent lot ;
2. After maintenance work on the analyzer; and
3. Control values are outside the confidence limits.
LINEARITY
The method is linear up to 150 g/l.
PROCEDURE
Wavelength: 546 nm ;
Room Temperature ;
Tank: 1 cm thick;
Adjusting the spectrophotometer zero with the reagent blank.
Blank Standard Sample
Standard
- - 20 µl - -
Sample
- - - - 20 µl
Working Solution
1 ml 1 ml 1 ml
Mix and read absorbances after 5 minutes incubation at room tempera-
ture. Staining stability is 30 minutes.
CALCULATION
Total proteins =
OD. Sample
OD Standard
x n
With n = Standard Value
n = 50 g/l ;
n = 5 g/dl.
REFERENCE VALUES
Newborns
52 - 91 g/l
5,2 - 9,1 g/dl
Children
54 - 87 g/l
5,4 - 8,7 g/dl
Adults
67 - 87 g/l
6,7 - 8,7 g/dl
REFERENCES
A. Gornall et al- J. Biol-Chem 177,751 (1949) ;
Henry R.J., Annal. Chem. 92, 1491 (1957) ;
Peter T.J. Clin. Chem. 14, 1147 (1968) ;
T.E. Weichselbaum: Am. J. Clin. Pathol. 16 Sect. 10-40 (1946).
