Selling unit: per 100ml
Product Name
1. Common name: Blood ammonia (MH3) assay kit (enzyme method)
2.English name: NH3Reagent Kit (Enzymatic Method)
Package specification
6:1
Intended use
This kit is used for the in vitro quantitative determination of blood ammonia (NH3 ) in human serum or plasma.
NH3 is present in very small amounts in the human body, but ammonia is toxic to the body and can affect the metabolism of nerve cells. An increase in the source and a decrease in the destination of blood ammonia can cause an increase in blood ammonia. Blood ammonia measurements are extremely important for the diagnosis and differential diagnosis of hepatic encephalopathy. Increased blood ammonia is commonly seen in a variety of liver diseases and comorbidities caused by other diseases, when liver failure occurs or when blood does not flow normally through the liver; adult blood ammonia measurements are mainly used for monitoring and management of hepatic coma.
Test Principle
In the presence of lactate dehydrogenase (LDH), pyruvate, which interferes with the determination of ammonia in serum, is removed in a pre-reaction. Ammonia reacts with α-KG and NADH in the presence of glutamate dehydrogenase, and the amount of ammonia in the serum can be calculated by comparison with the same treated calibration solution.
*Components are not interchangeable in kits with different lot numbers.
*Reagent components not included in the product, but necessary for the test: outsourced normal and abnormal QCs and calibrators.
Storage Conditions And Expiration Date
The kit is stored at 2-8°C away from light and is valid for one year.
Reagents that have been opened are careful not to be contaminated, and reagents are stable in the instrument compartment (2-8°C) for one month.
The reagents must not be frozen.
Applicable Instruments
Hitachi 7180/7600; Olympus AU680/2700; Toshiba TBA120; Myriad BS2000M/480; Siemens ADVIA 1800/2400 series automatic biochemical analyzers.
Sample Request.
Serum without hemolysis. Immediately after blood collection on an empty stomach, place the blood in ice water and separate the serum or plasma as soon as possible.
Store under cover at 2-4°C and analyze within 1.5-2 hours. Ice needs to be added to cool down in hot season to reduce
Slow blood deamination, otherwise the measured value will be low.
Test Method
- Reagent preparation: liquid reagent is used immediately after opening the bottle, reagent 1 (R1): mixed according to R1a:R1b=5:1; reagent 2 (R2): R2 can be used directly after opening.
- test conditions: (different parameters on the machine can be requested according to different testing instruments)
Operation steps.
Reagents and sample volumes can be increased or decreased in proportion to the requirements of different biochemical analyzers.
- Calibration procedure.
The use of matching calibrators is recommended.
- QC control procedures.
It is recommended that each laboratory establish its own quality control system and select appropriate quality control products for quality control. The measured values of QC products should be within the specified range. If outside the specified range, it is necessary to take appropriate measures or contact the manufacturer.
- Calculation.
The sample concentration values were derived from the calibration curve.
Positive Judgment Value Or Reference Interval.
20-47 µmol/L
It is recommended that each laboratory establish its own reference range of normal values.
Interpretation Of Test Results.
Ascorbic acid ≤ 30 mg/dL, bilirubin ≤ 40 mg/dL, and hemoglobin ≤ 200 mg/dL do not interfere with this test.
Limitations Of The Test Method.
The determination of NH3 in human serum or plasma is only one of the indicators used by the clinician to make a diagnosis of the patient. The clinician must also make a comprehensive judgment based on the patient’s physical symptoms, medical history and other diagnostic items and diagnostic tools.
Product Performance Index
Absorbance of reagent blank: wavelength 340 nm, optical diameter 1.0 cm, temperature 37°C, A0 ≥ 1.0.
Analytical Sensitivity: The kit tests 32 µmol/L of the analyte with an absorbance change of ΔA ≥ 0.01.
Linearity range: test serum samples, reagent linearity in the interval of 0-250 µmol/L, linear correlation coefficient|r| should not be less than 0.990; in the interval of 0-50 µmol/L, the absolute deviation of linearity should not exceed 5 µmol/L; in the interval of (50-250 µmol/L, the relative deviation of linearity should not exceed ±10%.
Precision: repeatability CV ≤ 5%; relative extreme difference between batches ≤ 8%.
Accuracy: Relative deviation ≤ 10%.
Caution
- This product is for in vitro diagnosis only.
- Avoid contamination when using the reagent, the container used must be clean, and please take necessary precautions, do not swallow, and avoid contact with skin and mucous membrane.
- Please dispose of the measured samples and waste liquids in accordance with the relevant national and local laws and regulations.
- When changing the reagent lot number, the calibration should be re-calibrated.
- Do not mix kits of different lot numbers and reagents left after use.
- test water, glass equipment should be done without ammonia treatment, and to prevent the pollution of ammonia in the environment.
Reference
Fully automated analysis of enzyme kinetic method for determination of blood ammonia. Shanghai Journal of Medical Laboratory, 1995.
