Blood test

Blood tests are laboratorytests done on bloodto gain an appreciation of diseasestates and the function of organs. Since blood flows throughout the body, acting as a medium for providing oxygenand other nutrients, and drawing waste products back to the excretory systems for disposal, the state of the bloodstream affects, or is affected by, many medical conditions. For these reasons, blood tests are the most commonly performed medical tests. Blood is obtained from a patient by venipuncture, except for tests such as Arterial blood gas.

Blood is useful as it is a relatively non-invasiveway to obtain cells, and extracellular fluid(plasma), from the body to check on its health. Although the term blood test is used, most routine tests (except for most haematology) are done on plasmaor serum.

The list below includes both specific tests, and general techniques.

Blood chemistry tests

The CHEM-7 testis a battery of blood chemistry tests. The seven parts of a CHEM-7 include tests for:

• Four electrolytes:
  • sodium[1]
  • potassium[2]
  • chloride[3]
  • bicarbonateor CO₂ [4]
• blood urea nitrogen(BUN) [5]
• creatinine[6]
• glucose[7]. (This test can also be performed directly by diabeticpatients by using a glucose meter.)

One common use for these tests is to determine renal function.

While the regular glucose testis taken at a certain point in time, the glucose tolerance testinvolves repeated testing to determine the rate at which glucoseis processed by the body.

While the above tests are all taken from veinous blood, by constrast the arterial blood gastest is, as its name would suggest, taken from arterial blood, and is therefore more dangerous and uncomforable.

Large organic molecules

proteins

• Protein electrophoresis(general technique -- not a specific test)
• Western blot(general technique -- not a specific test)
• Liver function tests

Antibody proteins

• Serology (general technique -- not a specific test)
  • Wassermann test(for syphilis)
• ELISA test
• Cold agglutinins test[8]

Other

• Polymerase chain reaction(DNA). DNA testingis today possible with even very small quantities of blood: this is commonly used in forensic science, but is now also part of the diagnostic process of many disorders.
• Northern blot(RNA)

Cells

• Full blood count(or "complete blood count")
• Hematocritand MCV("mean corpuscular volume")
• Erythrocyte sedimentation rate(ESR)
• Cross-matching. Determination of blood typefor blood transfusionor transplants
• Blood culturesare commonly taken if infection is suspected. Positive cultures and resulting sensitivity results are often useful in guiding medical treatment.

See also

• Reference ranges for common blood tests(with a much longer list)
• Urine test
• Blood diseases
• HIV test(uses several different techniques, including ELISA testand Western blot)
• Blood film
• Hematology
• Microbiologyhe:????? ??

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This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Blood+test Wikipedia article Blood test.