Notes: 2’-Deoxyuridine-d2 is intended for use as an internal standard for the quantification of 2’-deoxyuridine (Item No. 27803) by GC- or LC-MS. 2’-Deoxyuridine is a pyrimidine nucleoside composed of the pyrimidine base uracil (Item No. 26088) attached to the sugar deoxyribose.{45276} It has been used as a precursor in the synthesis of antiviral deoxyuridine derivatives, including idoxuridine (Item No. 20222).{45278,45279} Formulations containing 2’-deoxyuridine have been used in the deoxyuridine suppression test to identify vitamin B12 and/or folate deficiency and in the diagnosis of megaloblastic anemias.