S. Creatinine
A serum creatinine test is a medical diagnostic test used to measure the level of creatinine in the blood. Creatinine is a waste product produced by the muscles as they break down a compound called creatine phosphate, which plays a crucial role in muscle contraction. This test is an essential tool in assessing kidney function and is often used in conjunction with other tests to evaluate the health of the kidneys.
introduction to the serum creatinine test:
Purpose: The primary purpose of a serum creatinine test is to assess how well the kidneys are functioning. Kidneys filter waste products, including creatinine, from the blood and excrete them through urine. Elevated blood creatinine levels can be a potential indicator of compromised kidney function.
Kidney Function: Creatinine is a reliable marker for kidney function because it is produced at a relatively constant rate and is primarily excreted by the kidneys. When the kidneys are healthy, they efficiently remove creatinine from the blood, keeping its levels within a narrow range.
Definition: Medical Definition of Creatinine A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles Is called creatinine.
Principle of S. Creatinine: Alkaline solution with picric acid reaction to orange-red colored complex done by produce. the absorbance sample of this complex is contrition of sample is proportional.
Reaction Principle: Creatinine + Picric Acid = Creatinine-picrate complex (Golden yellow Color) - S. Creatinine Test color
Indication of s. creatinine test:
1. Urinary tract infection (UTI)
2. Nephrotic Syndrome
3. Acute Glomerulonephritis
4. Metabolic and Systemic diseases:
* Diabetes Mellitus (DM)
* Diabetes Insipidus
* Jaundice
5. To detect calculi in the urinary tract
6. Kidney failure
7. Enlargement of kidney
8. Damage of Kidney
Investigation of s. creatinine: The serum creatinine test is usually included in the renal function test or kidney function test. This test is usually performed by the doctor in the way- S. Creatinine, creatinine, crea,
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| S.Creatinine |
Sample Collection:
Specimen type: Plasma or Serum
Collection container: Gray tube or yellow vial.
Specimen: 2 ml of serum or plasma. no, not at all minimum 0.5 ml
Special notes: Outreach clients: Specimen may also be collected in gray-top tubes. Place specimen on centrifuge and separate plasma from cells
Patient preparation: A fasting specimen is not required. For fasting glucose, please order Fasting Plasma Glucose.
Specimen processing centrifuge : Plasma: Centrifuge at 2000-2500 rpm for a minimum of 10 minutes.
Serum: Allow to clot. Centrifuge at 2000-2500 rpm for a minimum of 10 minutes. For specimens collected in anything other than gray-top tubes, the sample is not suitable for glucose testing if it is not centrifuged within two hours of collection.
Transport temperature: Room temperature for 8 hours then refrigerated for 3 days.
Methods of S.creatinine Estimation: Fixed Time Kinetic Method
Reagent Preparation: 1 volume picric acid solution is diluted with 1 volume NaOH mix then working reagent.
Stability of working reagent: 15 days at 2 -8* c or 3 days at 20 -25* c.
Reagents required:
1. Picric Acid
2. Sodium hydroxide
3. Standard solution
Concentration Of standard: 2.0 mg/dl
Analyzer Parameter:
Wavelength / Filter: 510 nm (490-510)
Method: Fixed time kinetic
No of Readings: 1
Interval Time (Second): 120
Reaction Direction: Increasing
Reagent Volume: 1000 microliters
Sample Volume (ul): 100 microliters
Normal Low (mg/dl): 0.60
Normal High (mg/dl): 1.50
Linearity Low (mg/dl): 0
Linearity High (mg/dl): 13
Units: mg/dl
Test Procedure:
Reagent Standard Test
NaOH 500 microliters 500 microliters
Picric Acid 500 microliters 500 microliters
Standard 100 microliters ------
Sample ----- 100 microliters
Mix and pour immediately into the curette. after exactly 20 seconds A1 of sample and standard are read exactly 120 seconds after the first reading .A2 of sample and standard are read.
Delta A sample = A2-A1 Of sample
Delta A standard = A2-A1 Of the standard
Calculation and curve: od of sample/od of standard* s. creatinine concentration
Normal Value: Male: 0.6-1.5 mg/dl
Female: 0.5-1.3 mg / dl
Materials:
- Cotton
- Hexaso
- Tourniquet
- Gloves
- Marker Pen
- Test tube rack
- Disposable Syringe
- Gel tube / Yellow vial
- Stop Watch
- Calculator
- Colorimeter
- Semi-Auto analyzer
- Incubator
- Micropipette
Linearity: Linear Range: The serum creatinine test is generally linear within its specified range. This means that as the concentration of creatinine in the blood increases, the test results should also increase proportionally, allowing for accurate measurements within that range.
Limitations: However, like most laboratory tests, the serum creatinine test has limitations in its linear range. If creatinine levels are exceptionally high or low, the test may not provide accurate results. In cases of severely impaired kidney function or other medical conditions, the linear relationship may break down, and the test may not effectively reflect kidney health.
Dilution: In cases where creatinine levels are extremely high, a laboratory may need to dilute the blood sample to obtain a measurable result. The result is then adjusted based on the dilution factor to provide an accurate creatinine level.
Caution and Interpretation:
Other Factors: While the serum creatinine test is an important indicator of kidney function, it's essential to consider other factors that can influence creatinine levels. These include age, gender, muscle mass, diet, and certain medications.
Muscle Mass: Individuals with a higher muscle mass tend to have higher creatinine levels because creatinine is produced by muscle metabolism. Therefore, low creatinine levels may be seen in people with muscle atrophy or reduced muscle mass.
Medications: Certain medications, such as antibiotics (e.g., cefoxitin), may temporarily increase creatinine levels without necessarily indicating kidney dysfunction. It's crucial for healthcare providers to consider the patient's medication history when interpreting results.
Age and Gender: Normal creatinine levels can vary with age and gender. Pediatric and elderly populations may have different reference ranges.
Non-Renal Causes: Elevated creatinine levels can sometimes be due to non-renal factors, such as dehydration or conditions affecting muscle breakdown.
Acute vs. Chronic Changes: A single creatinine measurement may not provide a complete picture of kidney function. Monitoring trends in creatinine levels over time is often more informative. Acute changes may indicate sudden kidney injury, while chronic changes may suggest chronic kidney disease.
Creatinine is an important test care must be taken when testing blood sugar to avoid hemorrhagic blood you have to do QC every day as well as run standard
Reagent company name:
- 1 .TRADSWORTH LTD (Human GmbH, Germany)
- 2. GENETIC TRADING
- 3. MEDI-VISION LTD
- 4. BIO-TRADE INTERNATIONAL
- 5. BIO-MEDICAL LIMITED
- 6. MEDITECH
- 7. HEALTH CARE TECHNOLOGIES
- 8. RAJANIGANDHA INTERNATIONAL
- 9. RANDOX
- 10.PLASMATEX
- 11. LEIZ SUPPLY AGENCY
- 12. ABC INTERNATIONAL
- 13. ROSE INTERNATIONAL
- 14. BIOZEN.
