Catalog Entry Information

Batch numbers

Batch numbers can be found at the top of the product data sheet, or on the vial label, as a 1, 2 or 3 digit number, to the left of a letter. The numbers to the right of this letter are for internal use only. For example, in the case 15A/466444, 15 identifies the batch number.

Chemical Abstracts Registry (CAS) numbers

The Chemical Abstracts Service (CAS) number is a unique identification code assigned to a chemical substance by the American Chemical Society. While these are given as accurately as possible they may not always reflect the salt or level of hydration of the product supplied.

Molecular weights

The molecular weight displayed in our catalog represents the product as determined by its chemical structure.

For further information, including molecular weight variation between batches, please visit our molecular weight support page.


Where specific stereochemistry is indicated in a diagram, the product is supplied in the conformation shown. When products are supplied as mixtures of stereoisomers, for clarity only one form is shown. The existence of both enantiomers in a product is indicated by the notation 'and enantiomer'.

Weighing accuracies

The quantity of compound supplied in our vials is not weighed to the accuracy required for direct solution preparation unless specifically stated on the product datasheet. It is the responsibility of the individual researcher to accurately reweigh the compound in order to obtain solutions of defined concentration.

Please complete a technical enquiry form if you don't find the answer you are looking for.

Alternatively, please contact us for further information and assistance.

View all Technical Support common questions.

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