Medical and metrological vocabulary - Dynamic NPU Manual

Medical and metrological vocabulary


Description of why and how concepts are traceable and defined by international vocabulary


All concepts must be defined by international nomenclature, ontology or terminology (Principles of NPU terminology)


Sources to bodies of terms used with a particular technical application in medical, clinical laboratory and metrological fields (see Table of terminology references)


A NPU definition can be defragmented into individual concepts



Concept field





Clinical and Laboratory Standards Institute – Approved Guideline I/LA20-A2 Clinical and Laboratory Standards Institute – Approved Guideline I/LA20-A2  (previously NCCLS) CLSI identifiers

Blood types

International Society of Blood Transfusion (ISBT 128) None

Certified Reference Material (CRM, preparations)

World Health Organization, International Biological Reference Preparations WHO Reference Preparation

Chemical substances (substances with low molecular weight)

Chemical Abstract Services (CAS)

Inchi system (IUPAC)

CAS registry (Inchi key (IUPAC))

Note: The chemical substances are termed according to the above homepages in that order. In practice, if the first homepage can’t identify or define the chemical substance, the chemical substance termed according to the next (if found).


International Union of Biochemistry and Molecular Biology Enzyme Committee

Note: Focus on protein function

Enzyme Commission (EC)

Gene phenotypes

Mendelian Inheritance in Man OMIM database

General medical concepts, and substances without chemical definitions

Medical Subject Headings (MeSH)

NCI Thesaurus

MeSH Unique ID

NCI Thesaurus ID

Note: Both references above can be used but the definitions should be scrutinized in both references. Selective choices (cherry picking) can appear.

Genomic DNA sequences

Locus Reference Genomic LRG

Human genes

HUGO Gene Nomenclature Committee HGNC gendatabase

Internal definitions

Established terms that do not exist in any international terminology references QU ID

(Download the CSV-file termed: ‘English version: All concept elements in use this date’)

International Nonproprietary Name (INN)

International Nonproprietary Nameof medicines None

Living organisms

Taxonomy for organisms NCBI ID




”Silver book” [2]


Metrological terms

International vocabulary of metrology None

Measurement units

Bureau International des Poids et Mesures None

Prokaryotic organisms

List of prokaryotic names with standing nomenclature (LPSN) NCBI ID

Note: For administration purposes, the NCBI taxonomy ID is chosen.


Universal Protein Resource (UniProt)

Note: Focus on protein structure


Note: Name of protein with a catalytic property use above enzyme nomenclature


International Commitee on Taxonomy of Viruses (ICTV) NCBI ID

Note: For administration purposes, the NCBI taxonomy ID is chosen.





2023-12-06 Glycoproteins and glycolipids At this point, there are no stable and international terminology references for these two subjects  
2023-12-06 Avoiding duplicate terms (two or more terms that have same definitions) The threshold between similar terminology references can be discrete for a given term. Establishing a term in the NPU terminology must be used with caution to avoid duplicate terms.

Aspartate transaminase (Identifier E.C. is termed in Expasy and Aspartate transaminase, cytoplasmatic in UNIPROT (P17174).

Note: In this case, the first term was chosen.

2023-12-06 Criteria to the terminology reference

Terminology references are chose by the following criteria:

  • Stable organisation behind the terminology
  • Online available
  • Internationally approved
  • Well defined content

Note: C-NPU approves or disapproves a potential terminology reference in interest.

2023-12-06 Terms with internal definitions To establish a term that is not identified in any terminology references, terms with internal definitions may be neccessary to establish, using the vocabulary of the NPU terminology. This should be the last resort. ‘Zolpidem/Creatininium’ is defined as: “the  coefficient of the quantity of Zolpidem (CAS82626-48-0) relative to the quantity of Creatininium (CAS60-27-5)”
2023-12-06 Inchi system IUPAC’s Inchi system is  under trial.