Arbitrary substance concentration (arb.subst.c.)
Abbreviation 
Arb.subst.c.  

Definition in words 
Arbitrary amountofsubstance of component B divided by volume of system 1  
Definition by equation 
Note: k_{procedure} is a constant defined by the measurement procedure (there is an approximately proportionality to a kindofquantity from the International System of Quantities). 

Ratio scale 



Unit 
International unit (IU) or procedure defined unit (p.d.u.) (nonSI units)  
Special rule(s) in the NPU syntax 
“Procedure” is stated in the specification to the kindofproperty in the NPU definition. “Procedure” indicates that the measurement procedure must be stated somewhere else than the NPU code and there may be difficulties in comparing values for the same NPU code. If the unit is an International Unit (IU), an international certified reference material (e.g. WHO reference material) is specified in the specification to the kindofproperty. If there exist no international certified reference material, the laboratory can specify the unit at the placeholder, procedure defined unit. 

Reference 
Ferard G, Dybkaer R, FuentesArderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451. 
Laboratory field 
Examples 


Allergology 
Example 1  
Generic abbreviated form  NPU56406 P—Immunoglobulin E; arb.subst.c.(IS 11/234; proc.) = 10 × 10^{3} IU/L  
Full form with a result  NPU56406 Plasma—Immunoglobulin E; arbitrary substance concentration(IS 11/234; procedure) = 10 × 10^{3} International Unit per litre  
Abbreviated form with a result  NPU56406 P—Immunoglobulin E; arb.subst.c.(IS 11/234; proc.) = 10 × 10^{3} IU/L  
Written expression  The arbitrary substance concentration of Immunoglobulin E in Mr. Smih’s plasma is [10] × 10^{3} IU/L. The measurement is performed by a procedure defined by the laboratory. “IU” and its magnitude is defined by the Certified Reference Material, IS 11/234 from WHO.  
Equation  
Clinical Chemistry 
Example 2  
Generic abbreviated form  NPU58412 P—Choriogonadotropin+betachain; arb.subst.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU58412 Plasma—Choriogonadotropin+betachain; arbitrary substance concentration(procedure) = 24 arbitrary unit per litre  
Abbreviated form with a result  NPU58412 P—Choriogonadotropin+betachain; arb.subst.c.(proc.) = 24 arbitrary unit/L  
Written expression  The arbitrary substance concentration of Choriogonadotropin+betachain in Mrs. Smith’s plasma is [24] arbitrary unit/L. The measurement is performed by a procedure defined by the laboratory.  
Equation


Notes

“Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit. and not an accepted international unit.  
Clinical Phamarcology 
Example 3  
Generic abbreviated form  NPU57089 P—Rituximab antibody; arb.subst.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU57089 Plasma—Rituximab antibody; arbitrary substance concentration(procedure) = 2 arbitrary unit per litre  
Abbreviated form with a result  NPU57089 P—Rituximab antibody; arb.subst.c.(proc.) = 2 arbitrary unit/L  
Written expression  The arbitrary substance concentration of Rituximab antibody in Mr. Smith’s plasma is [2] arbitrary unit/L. The measurement is performed by a procedure defined by the laboratory.  
Equation  
Notes  “Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit. and not an accepted international unit.  
Clinical Immunology and Blood bank 
Example 4  
Generic abbreviated form  NPU26643 P—DNA topoisomerase 1 antibody(IgG); arb.subst.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU26643 Plasma—DNA topoisomerase 1 antibody(Immunoglobulin G); arbitrary substance concentration(procedure) = 37 ELISA unit/L  
Abbreviated form with a result  NPU26643 P—DNA topoisomerase 1 antibody(IgG); arb.subst.c.(proc.) = 37 ELISA unit perlitre  
Written expression  The arbitrary substance concentration of DNA topoisomerase 1 antibody(Immunoglobulin G) in Mr. Smith’s plasma is [37] ELISA unit/L. The measurement is performed by a procedure defined by the laboratory.  
Equation  
Notes  “ELISA unit” was chosen by a local laboratory as a proprietary measurement unit. and not an accepted international unit.  
Clinical Microbiology 
Example 5  
Generic abbreviated form  NPU29472 P—Tickborne encephalitisvirus antibody(IgG); arb.subst.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU29472 Plasma—Tickborne encephalitisvirus antibody(Immunoglobulin G); arbitrary substance concentration(procedure) = 125 Multiplate unit/L  
Abbreviated form with a result  NPU29472 P—Tickborne encephalitisvirus antibody(IgG); arb.subst.c.(proc.) = 125 Multiplate unit/L  
Written expression  The arbitrary substance concentration of Tickborne encephalitisvirus antibody(Immunoglobulin G) in Mr. Smith’s plasma is [125] Multiplate unit/L. The measurement is performed by a procedure defined by the laboratory.  
Equation  
Notes  “Multiplate unit” was chosen by a local laboratory as a proprietary measurement unit. and not an accepted international unit.  
Reproduction and Fertility 
Example 6  
Generic abbreviated form  NPU01574 SemP—Chorionic Gonadotropin; arb.subst.c.(IS 75/537; proc.) = ? IU/L  
Full form with a result  NPU01574 Seminal Plasma—Chorionic Gonadotropin; arbitrary substance concentration(IS 75/537; procedure) = 6 International Unit per litre  
Abbreviated form with a result  NPU01574 SemP—Chorionic Gonadotropin; arb.subst.c.(IS 75/537; proc.) = 6 IU/L  
Written expression  The arbitrary substance concentration of Chorionic Gonadotropin in Mr. Smith’s seminal plasma is [6] IU/L. The measurement is performed by a procedure defined by the laboratory. “IU” and its magnitude is defined by the Certified Reference Material, IS 75/537 from WHO.  
Equation  
Thrombosis and Haemostasis 
Example 7


Generic abbreviated form  NPU28289 P—Fibrin Ddimer; arb.subst.c.(proc.) = ? (p.d.u.)  
Full form with a result  NPU28289 Plasma—Fibrin Ddimer; arbitrary substance concentration(procedure) = 5 FEU  
Abbreviated form with a result  NPU28289 P—Fibrin Ddimer; arb.subst.c.(proc.) =5 FEU  
Written expression  The arbitrary substance concentration of Fibrin Ddimer in Mr. Smith’s plasma is [5] FEU. The measurement is performed by a procedure defined by the laboratory.  
Equation  
Notes  “FEU” was chosen by a local laboratory as a proprietary measurement unit. and not an accepted international unit.  
Reference 
NPU database, https://www.ifcc.org/ifccscientificdivision/sdcommittees/cnpu/npusearch/ and http://www.labterm.dk/default.aspx 

Kindofproperty

Nominal kindofproperty

Kindofquantity

Ordinal kindofquantity

Unitary kindofquantity

Rational unitary kindofquantity

 Arbitrary substance concentration
 Arbitrary substance concentration




Reference 

Date  Term  Note 

19960101  Arbitrary substance concentration  Term established 
NPU term identifier 
QU50106 