An assay is an analytic test to detect the presence, measure the concentration, and determine the biological activity of molecule, ions, or cells. Assays are based on measurable parameters that enable the evaluation of differences between samples and controls. Sensitivity, the ability to detect small amounts of a substance, and specificity, the ability to detect only the analyte, are essential features of an assay.

See also Bioassay, Biochemical, Biohazards, Biokinetic Model and Bioaccumulation Factor.

(Bq) Becquerel is the system international (SI) since 1985 new unit of radioactivity. 1 becquerel is equal to 1 disintegration per second.
1 Bq = 0.027 x10^-9 Ci (Curie).
In medicine and radiation protection the SI measurement units of becquerel, gray and sievert (should) have replaced the conventional units of curie, rad and rem.

To convert:


See also Gray, Sievert, Roentgen Equivalent In Man, Radiation Absorbed Dose, Count and Becquerel Antoine Henri.

Discovered the radioactivity in 1896.

A bone scintigraphy is a nuclear medical test used to detect increased calcium metabolisms with technetium labeled diphosphonates. Pathological bone processes present themselves primarily as activity enrichment.

See Bone Scan and Multiphase Bone Scintigraphy.

(C, c, Ci) Curie is an obsolete unit of radioactivity; superseded by the SI unit becquerel.
1 curie is 3.70 x10¹⁰ disintegrations per second or 37,000 MBq. Formerly it was defined as the radiation emitted by 1 g of radium.
The curie is originated on Marie (1867-1934) and Pierre (1859-1906) Curie, (French chemists and physicists and Nobel laureates).

See Becquerel.