marker

marker /mark·er/ (mahrk´er) something that identifies or that is used to identify.

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tumor marker  a biochemical substance indicative of neoplasia, ideally specific, sensitive, and proportional to tumor load.

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mark·er (märkr)

n.

1. One that marks or serves as a mark.

2. A physiological substance, such as human chorionic gonadotropin or alpha-fetoprotein, that may indicate disease when present in abnormal amounts in the serum, as that caused by a malignancy. Also called biomarker.

3. A genetic marker.

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marker

a visual or electronic signal that permits identification and therefore sorting of individual items from a group.

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marker animals

males or teasers wearing chin-ball or siresine harness so that females mounted are marked by crayon or paint.

marker genes

genes with a known location on a chromosome and an obvious phenotype which are used as reference points when mapping other genes.

histochemical marker

marking of cells or tissues based on a chemical identification of the contents; the location of specific chemical substances in particular locations is marked by the installation of an electronic or color signal.