Tests affected by carry over of EDTA
- Ca
- PT/PTT
- Potassium and Sodium
- Alkaline phosphatase
- Serum Iron
This anticoagulant can beused for some biochemistry
but is not suitable for:
Alkaline phosphatase –falsely decreases alkaline
phosphatase by bindingmagnesium.
Potassium and sodium -due to the addition of potassium to the sample –falsely increases potassium levels
Calcium and magnesium -these are chelated
(binded) by the EDTA.
Tests affected by carry over of Heparin
- Coagulation Studies
- Sodium (Na Heparin tube)
- Lithium (Li Heparin tube)
- Blood urea nitrogen (Ammonium Heparin tube)
- Ammonium (ammonium Heparin tube)
- Some heparin tubes have a gel for separation
- Acid phosphatase
Accelerates the action of antithrombin and prevents
clot formation This anticoagulant is not
suitable for haematology test, calcium, sodium or lithium as the heparin alters the cell morphology
Tests affected by carry over of Citrate
- Alkaline Phosphatase
- Calcium
- Phosphorous
Inhibits and decreases ALP
Binds to calcium
Tests affected by carry over of Potassium Oxalate
- Potassium and calcium
- Acid and Alkaline Phosphatase
- Amylase
- PT/PTT
- LD
- RBC Morphology
oxalate damages cell membranes and causes abnormal RBC morphology. Oxalate interferes in enzyme reactions.
Tests affected by carry over of Silica (clot activator)
• PT/PTT
Tests affected by carry over of Sodium Fluoride
- Sodium
* Urea Nitrogen
