California Mastitis Test Schalmtestplatte

The California mastitis test (CMT) is a simple

cow Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

-side indicator of the

somatic cell count A somatic cell count (SCC) is a cell count of somatic cells in a fluid specimen, usually milk. In dairying, the SCC is an indicator of the quality of milk—specifically, its low likeliness to contain harmful bacteria, and thus its high food s ...

milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...

. It operates by disrupting the

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

of any cells present in the milk sample, allowing the DNA in those cells to react with the test reagent, forming a

gel A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still dif ...

. It provides a useful technique for detecting

subclinical In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asym ...

cases of

mastitis Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs ...

Development

Whiteside described a reaction between

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali ...

and milk that resulted in the thickening of mastitic milk. The utility of this reaction as a field test was limited by the fact that the reaction was sometimes difficult to observe, and would eventually occur even in normal milk. A refined version of the test, which enhanced its sensitivity, and eliminated the confounding effect of milk fat, uses an anionic

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...

, which forms a gel with the DNA in

somatic cells A somatic cell (from Ancient Greek σῶμα ''sôma'', meaning "body"), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Such cells compo ...

in the milk.

Use

A four-well plastic paddle is used, one well being for each quarter of the cow to be tested. Foremilk is discarded, and then a little milk drawn into each well. An equal volume of test reagent is added, and gently agitated. The reaction is scored on a scale of 0 (mixture remains unchanged) to 3 (almost-solid gel forms), with a score of 2 or 3 being considered a positive result. A special reagent for the test is marketed under the name 'CMT-Test', but domestic detergents are frequently used instead, being cheaper and more readily available.

Fairy Liquid Fairy is an international brand, primarily used for washing up liquid and dishwasher detergent, owned by the American multinational consumer products company, Procter & Gamble. The brand originated in the United Kingdom and is now used on a numbe ...

is as suitable as a reagent for the CMT, although many cheaper detergents are not.

References

{{DEFAULTSORT:California Mastitis Test Bovine health Medical tests Veterinary procedures