Purpose of the Test
To determine the level of phosphorus in serum by spectrophotometric method.
Principle
Inorganic phosphorus reacts with ammonium molybdate in an acidic solution to form phosphomolybdic acid which is then reduced by aminonaphtholsulfonic acid to form a blue colored complex. The intensity of the color formed is proportional to the amount of phosphorus present in the sample.
Equipments
1. Spectrophotometer
2. Cuvettes
3. Micropipettes
4. Test tubes
5. Timer
6. Ammonium molybdate solution Reagent
7. Aminonaphtholsulfonic acid reducer
To Prepare Working Reagent Mix Equal Volume from R1 and R2
Sample Type
Serum or plasma is acceptable for the Test
Procedure
1. in 3 clean dry tubes add reagents and sample as mentioned in the Table below
| Blank | Standard | Test | |
|---|---|---|---|
| Phosphorus Working Reagent (R1 500 + R2 500) | 1000 μl | 1000 μl | 1000 μl |
| STD | – | 10 μl | – |
| Sample (Serum) | – | – | 10 μl |
Procedure
2. Mix Well and incubate for 10 mins at room Tempreature or 5 min @ 37c’
3. using the colorimeter or spectrophotometer read the absorbance against blank at filter wavelenght 340 nm
4. then do the calculations based on the following formula
Glucose = Absorbance of test / Absorbance of standard x Conc of standard
The STD Conc is 4 mg/dl or may vary depending on the reagent brand.
Reference range:
Adult: 2.5 – 4.5 mg/dL
Child: 4 – 7 mg/dL
Normal Range
Quality Control:
1. Run assayed quality control material with each batch of samples.
2. Results should fall within established confidence limits.
3. Review QC results and take appropriate corrective action if needed.
Warning :
1. Hemolysis causes falsely Elevated results.
M. Sulieman
mohammad@mlsgaate.com
Check phosphorus reagent expiration. Inspect instrument and calibrate if needed. Follow SOP for serum phosphorus testing.
تحقق من انتهاء صلاحية كاشف الفوسفور. افحص الجهاز وقم بالمعايرة إذا لزم الأمر. اتبع الإجراء المعياري القياسي لاختبار الفوسفور في الدم.
