For in vitro diagnostic use only
Do not pipette by mouth
Exercise the normal precautions required for handling
laboratory reagents
*Procedure
POTASSIUM
Turbidimetric Method
*Principle
The POTASSIUM with Tetraphenylborate, at light alcaline
pH, yelds a turbid complex.
Intensity of the turbidity, measured photometrically at 630
nm., is proportional to the concentration of Potassium in the
sample.
*Reagents composition, Contents and Safety warnings
Reagent 1
Potassium standard
5 mEq/l
Reagent 2
Tris Buffer
pH 7.5
50 mmol/l
Sodium tetraphenylborate
102 mmol/l
Boric acid
258 mmol/l
According to the present laws the kit does not contain
substances classified as dangerous.
The Reagent (Refer to instructions/safety data sheet), if
swallowed also taken in small doses, can represent a
danger for health.
Storage and Stability of Reagents
Store the Reagent at Room Temperature and the
standard at 2 - 8°C.
All the reagents are stable until the stated expiration date if
stored tightly closed.
Preparation and Stability of Working solution
Reagent
standard
liquid and ready to use *
liquid and ready to use
* Note: Just before use, shake the reagent vial to
resuspended any sodiumphenylborate deposited on
the bottom
Bring the Calibrator at Room Temperature before use
Sample
Fresh serum or Heparinized plasma
Safety precautions
Pipette into cuvettes
Distilled water
Sample
standard
Reagent
E. ACCURACY
Comparation betweeen this method (y) and another
commercial one (x), gave the following results:
N = 20
r = 0.982868
y = 0.9748x + 0.162
F. INTERFERENCES
Bilirubin till to15 mg/dl does not interfere
Blank
20 µl
Sample
standard
20 µl
1 ml
1 ml
20 µl
1 ml
Mix, incubate for 5 minutes at Room Temperature.
Read the absorbance of standard and Samples against the
Blank at Wavelength of 620 nm.
Final color is stable at least 30 minutes.
Calculation
Serum/Plasma
A Sample
Potassium (mEq/l) =
x standard Value
A standard
Quality Control
Control sera are recommended to monitor the performance
of assay procedures
Note
Use plastic or new glass disposables. Alternatively use
glass washed with Hydrocloric acid.
Bibliography
1. Henry R. J.: Clinical Chemistry, Harper and Row. N.Y.
646 (1974)
2. Tietz N. W.: Fundamentals of Clin. Chem., Saunders
Co., Philadelphia Sec. Edit 876 (1976)
For in vitro diagnostic use only.
The following symbols are used on labels
Reference values
Serum/Plasma:
3.6 - 5.5 mEq/l
For in vitro diagnostic use
These values should only be used as a guideline
Each laboratory should establish its Normal Reference
Range
Temperature limitation
Performance Characteristics
A. LINEARITY LIMIT
The reaction is linear till to 10 mEq/l
For higher value dilute sample 1:2 with Distilled water,
repeat the test and multiply the value by 2.
B. DETECTION LIMIT
Values less than 2.98 mmol/l give non - reproducible
results
C. INTRA - ASSAY PRECISION (N = 20 replicates)
Mean (mmol/l)
SD
CV%
Control 1
3.95
0.09
2.17
Control 2
5.95
0.12
2.04
D. INTER - ASSAY PRECISION (20 replicates for 3 days)
Mean (mmol/l)
SD
CV%
Control 1
4.01
0.09
2.42
Control 2
5.96
0.08
1.33
Use by (last day of the month)
Batch Code
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