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Medical Term:


Pronunciation: bī′ō-tin


The d-isomer component of the vitamin B2 complex occurring in or required by most organisms and inactivated by avidin; participates in biologic carboxylations. It is a small molecule with a high affinity for avidin that can be readily coupled to a previously labeled antibody to allow visualization by enzymatic or histochemical means.

Synonym(s): coenzyme R, vitamin H, W factor

See Also: avidin

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