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Naming Convention

HA’s web site and catalog uses the system of nomenclature known as the "square bracket preceding" system which is currently used by The American Chemical Society and many scientific journals. Products are listed alphabetically by the full chemical name followed by a bracket. The information within the bracket describes the location and type of radioactive label. The comma, space and hyphen indicate that everything between them should be placed before the chemical name to convert to the square bracket preceding. For example the Adenine, [8-14C]- listed in this catalog should be read as [8-14C] Adenine.

Specifically labeled compounds

Chemicals are designated as specifically labeled when all labeled positions are identified and the radioactivity at these positions is greater than 95% of the total incorporated into the compound. When more than one position is labeled, uniform or even distribution is not implied.

Uniformly labeled (U) compounds

This designation is reserved for compounds labeled in all positions in a uniform or nearly uniform pattern. This category includes compounds prepared by biosynthesis from carbon dioxide, [14C], or from a uniformly labeled intermediate.

Nominally labeled (N) compounds

This designation is used when the method of preparation requires some (usually a significant amount) of the label to be at a specific site or sites but no further information is available on the extent of labeling (if any) at other positions.

Generally labeled compounds

Compounds (usually tritium labeled) that do not have a specifically designated label position in which there is a random (i.e., non-uniform and undetermined) distribution of radioactivity at various positions. Under the conditions which lead to random labeling, many potential sites for labeling contain no radioactivity.