Novex IEF gels

Invitrogen Novex IEF Gels are used for determining the isoelectric point (pI) of proteins and are excellent for native applications.

Interactive selection toolAvailable Novex IEF Gels

Migration chart

Isoelectric focusing (IEF) is an electrophoresis technique that separates proteins based on their isoelectric point (pI). The pI is the pH at which a protein has no net charge and does not move in an electric field. Novex IEF Gels effectively create a pH gradient so proteins separate according to their unique pI. These gels can be used to determine the pI or to detect minor changes in a protein due to deamination, phosphorylation, or glycosylation. They can also resolve different proteins of similar size that cannot be resolved on standard SDS-PAGE gels. Novex IEF Gels are excellent for native, nondenaturing applications using soluble proteins. All Novex IEF Gels are provided at 1.0 mm thickness and a 5% acrylamide concentration.

IEF gels provide:

  • Clear, sharp bands for easy identification of protein modifications
  • Higher resolution of slight differences in size than SDS-PAGE
  • Accurate pI determination 
Available gel sizes Mini 8 x 8 cm (1 mm thick)
Storage conditions 2–8°C 
Shelf life 2 months
Available polyacrylamide concentrations 5%
Separation range pH 3–10 (pI performance range 3.5–8.0)
pH 3–7 (pI performance range 3.0–7.0)
For use with (equipment) mini gels Mini Gel Tank or XCell SureLock Mini-Cell
Mode of separation Isoelectric point

Proteins shown are:

1: amyloglucosidase (Aspergillus niger), pI = 3.5
2: glucose oxidase (Aspergillus niger), pI = 4.2
3: trypsin inhibitor (soybean), pI = 4.5
4a and 4c: β-lactoglobulin (bovine, milk), pI = 5.2 and 5.3
5: carbonic anhydrase (bovine, erythrocytes), pI = 6.0
6a and 6c: myoglobin (horse, muscle), pI = 6.9 and 7.4
7a, 7m, and 7c: lectin (Lens culinaris), pI = 7.8, 8.0 and 8.3; 8: ribonuclease A (bovine, pancreas), pI = 9.5
9: cytochrome c (horse, heart), pI = 10.7


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