Unit Conversion Table

A unit is defined according to the standard by which it is compared. For instance, the World Health Organization (WHO) offers protein reference standards that are accessible to everyone and allow for the normalization of activity definitions across proteins from different sources. These are available from NIBSC.

The activity of the protein reference standard is indicated by the number of units contained in a given mass of material. Typically, units are referred to as reference units (RU). When the reference material has been tested successfully in international, multi-center, collaborative studies it will be designated a WHO international standard, the units will then be International units (IU).

If there is a protein reference standard available, R&D Systems compares the activity of the reference standard with our protein, allowing for the conversion of mass into units (see table below).

Are all units the same?

No. One must be careful when comparing units of activity between sources. Different suppliers may have their own method for defining a unit. The method used, such as comparison with a WHO standard, must be the same between sources for a unit comparison to be valid. For this reason R&D Systems typically refers to proteins by their mass and activity by ED50.

Sample Conversion R&D Systems Recombinant Human BMP-2 to Equivalent Units

To calculate the approximate mass/concentration of an R&D Systems cytokine in units, multiply the mass/concentration (in µg) by the ‘R&D Systems Cytokine 1 µg = units’ column in the chart, the second column from the right. For instance, a 10 µg vial of rhBMP-2, catalog #355-BM, would contain 7,810 units (10 times 781).

Clear glass vials filled with multi-colored protein ribbons with white text overlay explaining GMP and Animal-Free proteins have lot-specific values on their CoAs.

R&D Systems Cytokine R&D Systems Catalog Number Reference Cytokine NIBSC Product Number Reference Standard Units/µg Cell Line used for Bioassay R&D Systems Cytokine 1 µg = units
rhActivin A 338-AC rhActivin A 91/626 1 K562 2.5
rhBDNF 248-BD rhBDNF 96/534 800 BaF/3 hTrkB 1.3 x 103
rhBDNF New! 11166-BD rhBDNF 96/534 800 BaF/3 hTrkB 1.4 x 103
rhBMP-2 355-BM rhBMP-2 93/574 500 ATDC-5 781
rhEGF 236-EG rhEGF 91/530 1.0 x 103 Balb-3T3 1.4 x 103
rhFactor II 1473-SE hThrombin 01/580 2.5 Boc-VPR-AMC Fluor Pep Sub 2.6
rhFGF-7 251-KG rhFGF-7 03/148 900 4MBr-5 520
rhFGF basic 233-FB rhFGF basic 90/712 800 NR6R-3T3 2.6 x 103
rhFGF basic 3718-FB rhFGF basic 90/712 800 NR6R-3T3 3.1 x 103
rhFSH 5925-FS rhFSH 92/642 13.8 HEK293/h FSH R 17.5
rhFlt-3 Ligand 308-FK rhFlt-3 Ligand 96/532 1.0 x 103 Baflt 1.2 x 103
rhG-CSF 214-CS rhG-CSF 88/502 1.0 x 105 NFS-60 2.6 x 105
rhGDNF 212-GD rhGDNF 09/266 500 SH-SY5Y 3.1 x 103
rhGH 1067-GH hGH 80/505 2.6 x 10-3 Nb2-11 5.4 x 10-3
rhGM-CSF 215-GM rhGM-CSF 88/646 1.0 x 104 TF-1 1.5 x 104
rmGM-CSF 415-ML rmGM-CSF 91/658 1.0 x 105 DA3 3.5 x 105
rhGRO alpha 275-GR rhGRO alpha 92/722 1.0 x 105 PMN 2.11 x 105
rhHGF 294-HG rhHGF 96/564 1.0 x 103 Saos-2 1.5 x 103
rhIFN-beta 8499-IF rhIFN-beta 00/572 2.0 x 105 HeLa 2.8 x 105
rhIFN-gamma 285-IF rhIFN-gamma 87/586 2.0 x 104 HeLa 2.0 x 104
rmIFN-beta 8234-MB mIFN-beta NR-3079** NA L929 1.2 x 106
rmIFN-gamma 485-MI rmIFN-gamma NIHGg02-901-533 1.0 x 103 L929 8.43 x 103
rhIGF-I 291-G1 rhIGF-I 91/554 1 MCF-7 1.9
rhIGF-II 292-G2 rhIGF-II 96/538 1000 MCF-7 850
rhIL-1 alpha 200-LA rhIL-1 alpha 86/632 1.0 x 105 D10.G4.1 1.6 x 105
rmIL-1 alpha 400-ML rmIL-1 alpha 93/672 1.0 x 106 D10.G4.1 7.1 x 105
rhIL-1 beta 201-LB rhIL-1 beta 86/680 1.0 x 105 D10.G4.1 1.4 x 105
rmIL-1 beta 401-ML rmIL-1 beta 93/668 1.0 x 106 D10.G4.1 1.1 x 106
rhIL-1ra 280-RA rhIL-1ra 92/644 1.0 x 10-3 D10.G4.1 1.0 x 10-3
rhIL-2 202-IL rhIL-2 86/500 1.4 x 104 CTLL-2 9.1 x 103
rhIL-2 New! BT-002 rhIL-2 86/500 1.4 x 104 CTLL-2 14.4 x 103
rmIL-2 402-ML rmIL-2 93/566 1.0 x 105 CTLL-2 2.5 x 105
rhIL-3 203-IL rhIL-3 91/510 1.7 x 103 TF-1 1.8 x 103
rmIL-3 403-ML rmIL-3 91/662 1.0 x 105 NFS-6 1.7 x 105
rhIL-4 204-IL rhIL-4 88/656 1.0 x 104 TF-1 1.7 x 104
rhIL-4 New! BT-004 rhIL-4 88/656 1.0 x 104 TF-1 2.0 x 104
rmIL-4 404-ML rmIL-4 91/656 1.0 x 104 HT-2 1.8 x 105
rhIL-5 205-IL rhIL-5 90/586 1.0 x 104 TF-1 4.4 x 104
rhIL-6 206-IL rhIL-6 89/548 1.0 x 105 T1165.85.2.1 1.1 x 105
rmIL-6 406-ML rmIL-6 93/730 1.0 x 105 T1165.85.2.1 9.0 x 105
rhIL-7 207-IL rhIL-7 90/530 1.0 x 105 activated PBL 1.6 x 105
rhIL-7 New! BT-007 rhIL-7 90/530 1.0 x 105 activated PBL 2.0 x 105
rmIL-7 407-ML rmIL-7 93/740 5.0 x 104 activated PBL 1.5 x 105
rhIL-8 208-IL rhIL-8 89/520 1.0 x 103 PMN see below*
rhIL-9 209-IL rhIL-9 91/678 1.0 x 104 MO7e 8.4 x 103
rmIL-9 409-ML rmIL-9 93/504 NA TS1 0.9 µg
rhIL-10 217-IL rhIL-10 93/722 5.0 x 103 MC/9 1.45 x 104
rhIL-11 218-IL rhIL-11 92/788 1.0 x 104 T11 1.05 x 104
rhIL-11 New! 10836-IL rhIL-11 92/788 1.0 x 104 T11 1.02 x 104
rhIL-12 219-IL rhIL-12 95/544 1.0 x 104 PBL 1.1x 104
rhIL-12 New! 10018-IL rhIL-12 95/544 1.0 x 104 PBL 1.54 x 104
rhIL-13 213-ILB rhIL-13 94/622 1.0 x 103 TF-1 780
rhIL-15 247-IL rhIL-15 95/554 1.0 x 104 MO7e 4.5 x 105
rhIL-15 New! BT-015 rhIL-15 95/554 1.0 x 104 MO7e 7.5 x 105
rhLeptin 398-LP rhLeptin 97/594 800 BaF3/h OB R 1.2 x 103
rmLeptin 498-OB rmLeptin 97/626 1.0 x 103 BaF3/h OB R 1.7 x 103
rhLIF 7734-LF rhLIF 93/562 1 x 104 TF-1 1.27 x 104
rhM-CSF 216-MC rhM-CSF 89/512 6.0 x 104 M-NFS-60 1.68 x 105
rhMCP-1 279-MC rhMCP-1 92/794 1.0 x 103 MNC 1.36 x 103
rhMCP-2 281-CP rhMCP-2 96/594 2.5 x 103 MNC see below*
rhMIP-1 alpha 270-LD rhMIP-1 alpha 92/518 100 MNC 200
rhMIP-1 beta 271-BME rhMIP-1 beta 96/588 1.0 x 103 MNC 1.6 x 103
rhbeta-NGF 256-GF rhbeta-NGF 93/556 1.0 x 103 TF-1 1.0 x 103
rhNT-3 267-N3 rhNT-3 98/718 1.0 x 103 BaF/3 hTrkB 2.1 x 103
rhOSM 295-OM rhOSM 93/564 5.0 x 104 TF-1 6.2 x 104
rhPDGF-BB 220-BB rhPDGF-BB 94/728 750 NR6R-3T3 1.9 x 103
rhProlactin 682-PL rhProlactin 84/500 0.0212 Nb2-11 0.054
rhRANTES 278-RN rhRANTES 92/520 1.0 x 104 MNC 2.5 x 104
rhSCF 255-SC rhSCF 91/682 1.0 x 103 TF-1 1.3 x 103
rhSCF New! BT-SCF rhSCF 91/682 1.0 x 103 TF-1 1.8 x 103
porcine TGF-beta 1 101-B1 bTGF-beta 1 89/516 18750 HT-2 2.1 x 104
porcine TGF-beta 2 102-B2 hTGF-beta 2 90/696 2.0 x 104 HT-2 5.6 x 104
rhTGF-beta 240-B rhTGF-beta 1 89/514 1.9 x 104 HT-2 2.2 x 104
rhTGF-beta New! 7754-BH rhTGF-beta 1 89/514 1.9 x 104 HT-2 2.4 x 104
rhTGF-beta 2 302-B2 rhTGF-beta 2 90/696 2 x 104 HT-2 2.2 x 104
rhTGF-beta 3 243-B3 rhTGF-beta 3 09/234 1.9 x 104 HT-2 2.2 x 104
rhTGF-beta 3 New! 8420-B3 rhTGF-beta 3 09/234 1.9 x 104 HT-2 2.8 x 104
rhTNF-alpha 210-TA rhTNF-alpha 88/786 4.65 x 104 L-929 7.6 x 104
rmTNF-alpha 410-MT rmTNF-alpha 88/532 2.0 x 105 L-929 2.7 x 105
rhTNF-beta 211-TB rhTNF-beta 87/640 1.5 x 105 L-929 4.6 x 104
rhTRAIL 375-TEC(E. coli) rhTRAIL 04/166 1.0 x 104 L-929 5.6 x 103
rhTRAIL 375-TL(NS0) rhTRAIL 04/166 1.0 x 104 L-929 3.2 x 103
rhTSH 4610-TH rhTSH 94/674 6.7 x 10-3 HEK293/h TSH R 7.9 x 10-3
rhVEGF165 293-VE rhVEGF165 02/286 1.0 x 103 HUVEC 1.1 x 103
rhVEGF165 New! BT-VEGF rhVEGF165 02/286 1.0 x 103 HUVEC 0.9 x 103

* In side by side evaluation of this standard with R&D Systems product, the standard demonstrated much lower maximal signal and thus cannot be compared using ED50

**The reference material was obtained through the NIH Biodefense and Emerging Infections Research Resources Repository, NIAID, NIH.