Canis ISSN: 2398-2942

Blood biochemistry: total protein

Synonym(s): TP

Contributor(s): Kathleen P Freeman, Elisa Mazzaferro


  • Contains albumin and globulin fractions.
  • Globulin fraction = alpha, beta and gamma subfractions.
  • Absolute changes in albumin and globulin associated with wide range of clinical conditions.
  • Electrophoresis: separation of globulin sub-fractions provides further information.


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  • Biuret: standard method (colorimetric).
  • Calibrated refractometer: for rapid result.
  • Temperature-controlled instrument recommended.
  • Electrophoresis Serum protein electrophoresis : followed by scanning with densitometer to quantify individual globulin subfractions.


  • Biuret: widely available.
  • Refractometer: widely available.
  • Electrophoresis: commercial laboratories.



  • Biuret: accurate except at low levels (<10 g/l).
  • Refractometer: generally satisfactory for clinical purposes not sensitive enough to detect low levels of protein found in body fluids other than serum.


  • Biuret method highly specific for protein.

Technique (intrinsic) limitations

  • Usually must be interpreted in conjunction with other laboratory and clinical findings to reach a diagnosis.

Technician (extrinsic) limitations

  • Electrophoresis.
  • Biuret: hemolysis and/or lipemia may result in increased total protein.
  • Refractometer: usually slight to moderate hemolysis or icterus will not interfere with reading. Turbidity of lipemia interferes with light transmission and ability to obtain an accurate reading.

Result Data

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Further Reading


Referred papers

Other sources of information

  • Ettinger S J, Feldman E C , Cote E (eds) (2017) Textbook of Veterinary Internal Medicine. 8th edn. St Louis: Elsevier.
  • Stockham S L, Scott M A (2002) Fundamentals of Veterinary Clinical Pathology. Iowa: Iowa State Press.
  • Kaneko J J, Harvey J W & Brass M L (eds) (1997) Clinical Biochemistry of Domestic Animals. 5th edn. Boston: Academic Press.
  • Duncan J R, Prasse K W & Mahaffey E A (1994) Veterinary Laboratory Medicine. Clinical Pathology. 3rd edn. Iowa: Iowa University Press.