sgot_ast [Laboratory Service Sir T Hospital , Bhavnagar ]

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                          SGOT (AST) Examination Procedure

**1.Purpose of examination:** 
AST estimation from serum NADH  (without P-5’-P) Method.

**2.Responsibility and Authority:** 
  * Calibration: Technician 
  * Quality Control: Technician 
  * Routine operation: Technician 
  * Overall Monitoring: Quality Manager

**3.Sample Details:** 
  * Type of Sample: Serum,  
  * Type of container and additives: Plain without any additives 
  * Patient Preparation: As per Primary Sample Collection Manual [[sample_collection_manual|]]
  * Stability: At Room temperature 18°–28°C (64°–82°F) stability ≤ 24 hours
  * Handling and transport: As per Primary Sample collection manual 
  * Storage: 24 hours at 2-8° C

**4.Required Equipment:** 
  * Centrifuge, Auto-Pipette, Disposable Tips, Disposable sample cups, FullyAuto Chemistry Analyzer

**5.Required reagents:**
R1 L-aspartic acid (103.860 g/L),
lactate dehydrogenase (4.000 KU/L),
and malate dehydrogenase (2.000 KU/L).
R2  α-ketoglutaric acid (6.570 g/L).

**6.Reagent Handling**
  * Remove any air bubbles present in the reagents with a new applicator stick, or allow the reagents to settle at the appropriate storage temperature to allow the bubbles to dissipate. To minimize volume depletion, do not use a transfer pipette to remove bubbles
  * Reagent Storage and stability
  * Unopened reagent stable at 2-8°C until expiration date.
  * On board System temperature reagent is  stable for 30 days
  * Instability or deterioration should be suspected if there are precipitates, visible signs of leakage or
  * contamination, turbidity, or if calibration or controls do not meet the appropriate criteria.

**7.Calibration Procedure:**
  * SGOT Calibrators-WATER BLANK
  * Frequency:
  * Reagent lot change
  * QC out of range
  * After service or maintenance
  * Replacement in any parts of Instrument
**Procedure:**
  * Start the equipment.WDI abbotte fully.docx
  * Calibrators are ready to use.
  * Put calibrator 15-20 minutes at room temperature  
  * Prior to use, mix the contents by inverting the vial. Do not shake the vial to prevent foam formation. 
  * Take a 150 µl calibrator solution in to separate aliquot.
  * Go to the calibration and give the calibration order.
  * Verify calibration with at least two levels of controls
  * If control results fall outside acceptable ranges, root cause analysis or recalibration may be necessary.

**8.Quality control Procedure:**

  * **Name:** Bio Rad Level 1 & 2
  * **Frequency:** As per Quality Control Procedure

**Procedure for Reconstitution of IQC** 
  * Reconstitution of QC material with 5 ml Distilled water by using calibrated fixed volume pipette.
  * Leave to stand for 30 min in the dark place.
  * Swirl gently several times during the reconstitution period to ensure that the contents are completely dissolved.
  * Prior to use, mix the contents by inverting the vial. Do not shake the vial as the information of foam should be avoided. Ensure that no lyophilized material remains un-reconstituted.
  * Prepare aliquots of 150 µl from the reconstituted QC material.
  * Store these aliquots at -15° C to -20° C.
  * Prior to use, make sure that aliquots should be at room temperature for at least 15 min.
**Procedure to run IQC**
  - Press Control order 
  - Select Assay /Panel, to be run.
  - Select the control/s and its level/s
  - Give Carrier Number and Position number
  - Press F3 / Add order
  - Put respected carrier in RSH rack
  - Check IQC results, in case outliers call residents.

**9.Principle of the procedure used for examinations:**
  * AST present in the sample catalyzes the transfer of the amino group from L-aspartate to α-ketoglutarate, forming oxaloacetate and L-glutamate. Oxaloacetate in the presence of nicotinamide adenine dinucleotide (NADH) and malate dehydrogenase (MDH) is reduced to L-malate. In this reaction, NADH is oxidized to NAD+. The reaction is monitored by measuring the rate of decrease in absorbance at 340 nm due to the oxidation of NADH to NAD+.

**10.Sample Preparation:**
  * Required SampleVolume: 150 µl of the sample 
  * Temperature: 37° 
  * Take 150-200µl of the sample from Primary tube to the secondary aliquot. Write the sample ID on the aliquot. 
**Procedure to run Patient sample**
  * Press Patient order 
  * Select Assay /Panel, to be run.
  * Give Carrier Number and Position number
  * Press F3 / Add order
  * Put respected carrier in RSH rack

**11.Performance Characteristics:** 
  * Linearity:  5 to 4001 U/L
  * The limit of detection (LOD): 4 U/L
  * The limit of quantification(LOQ): 5 U/L        
  * Unit:U/L 


**Normal and critical ranges:**
Aspartate aminotransferase
^male^<35^U/L^
^Female^<31^U/L^


 

**12.Laboratory Clinical interpretation:**
AST is found to be elevated in alcohol-induced liver disease, viral hepatitis, cirrhosis and acute
fulminant hepatic failure.

**13.Interference and cross reaction:**
The Following analytes were tested up to the two levels indicated at SGOT concentrations of 30 U/L and 120 U/L, and found not to interfere:
  - No interference from Bilirubin up to 30 mg/dL 
  - No interference from Hemoglobin up to 62 mg/dL 
  - No interference from Intralipid up to 550 mg/dL
  - No interference from Sulfapyrdine up to 300 mg/dl 
  - No interference from Sufasalazine up to 300 mg/dl 
  - No interference from Temozolomyde up to20 mg/dl 

**14.Potential source of variation:** 
**Turn around time (TAT):**
**Routine:** 6.0 hours
**Urgent:** 2.0 hours

**15.Recording of observation:**
  * Software backup 
  * Machine raw data
**16.Storage & Disposal of waste**:Follow storage & discard procedure

**17.Environmental & Safety control:**
  * For in vitro diagnostic use
  * Do not use component before the expiration date
  * Do not mix material from different kit lot numbers.
  * Reagent 2 causes mild skin irritation.

**18.References:**
  - Burtis CA,Ashwood ER,editors,Tietz Textbook of clinical chemistry.
  - World health organization. Biosafety manual,3rd edition.
  - Clinical and laboratory std institute . Protection of Laboratory workers from occupationally acquired infection; Approved guideline -4th edition.
  -  Burtis CA,Ashwood ER,editors,Tietz Textbook of clinical chemistry
  - Kaplan LA,Pesce AJ editors. Clinical Chemistry Theory, Analysis, and Correlation, 3rd ed.

|**Printed copy of this document is considered uncontrolled.** It should be compared with controlled electronic copy before use|

^ Name of Laboratory : Laboratory Services Sir T. Hospital (LSSTH),Bhavnagar ^^^^
^Document No.1^**Document Name**: SGOT (AST) Examination Procedure^**Unique ID**:LSSTH /BIOCHEM/ SOP-5^^
^Issue No. : 01^Issue Date :30/04/2024^Page No.^^
^Amend No.^ Amend Date ^Prepared by: Section Incharge^Approved & Issued by: HOD,Biochemistry^