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Test ID: Lactic acid
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Lactic acid
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Useful For
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Diagnosing and monitoring patients with lactic acidosis.
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Method name and description
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Colorimetric assay
L‑lactate is oxidized to pyruvate by the specific enzyme lactate oxidase (LOD). Peroxidase (POD) is used to generate a colored dye using the hydrogen peroxide generated in the first reaction.The intensity of the color formed is directly proportional to the L-lactate concentration. It is determined by measuring the increase in absorbance.
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Clinical information
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Anaerobic glycolysis markedly increases blood lactate and causes some increase in pyruvate levels, especially with prolonged exercise. The common cause for increased blood lactate and pyruvate is anoxia resulting from such conditions as shock, pneumonia and congestive heart failure. Lactic acidosis may also occur in renal failure and leukemia. Thiamine deficiency and diabetic ketoacidosis are associated with increased levels of lactate and pyruvate.
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Specimen type / Specimen volume / Specimen container
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Specimen type: Plasma
Minimum volume of sample: 1 mL
Plasma: NaFl (Grey) tube
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Collection instructions / Special Precautions / Timing of collection
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Lactate level increases rapidly with physical exercise. The time required for return to normal lactate values depends on the physical fitness of the subject. 30 minutes at rest is usually enough for this purpose.
Blood samples should be drawn from a stasis‑free vein. However, minimal hemostasis (less than 30 seconds) will not affect lactate levels. Avoid the use of a tourniquet, if possible.
Collect blood by standard venipuncture techniques as per specimen requirements. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
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Storage and transport instructions
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Storage seperated plasma:
8 hours at 15 – 25°C
14 days at 2 – 8°C;
Transport: 2-25°C
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Specimen Rejection Criteria
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Grossly hemolyzed, icteric and lipemic samples, wrong collection container, insufficient sample.
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Biological reference intervals and clinical decision values
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Turnaround time / Days and times test performed / Specimen retention time
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Daily (24/7)
Turn-around time:
STAT: 1 hour
Routine: One working day
Specimen Retention: 4 days
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