Technical information > IgG

Quick facts about IgG

IgG is the main low molecular weight immunoglobulin present in mammalian serum, and makes up 75% of serum immunoglobulins.

• Molecular mass: ~150 to 170 kDa depending on the species. IgG consists of two light chains and two heavy chains connected by disulfide bonds. The light chains have a molecular weight of around 23 kDa each, while the heavy chains are around 50 kDa each for H chain subclass ϒ1,2,4, and 60 kDa for ϒ3.
• Isoelectric point: 6.1-8.5 (7.3 ± 1.2) if monoclonal (polyclonal antibodies do not have a set isoelectric point as they are a pool of various classes).
• Concentration in serum: 10-20 mg/ml
• Glycosylation (by weight): 3%
• Extinction coefficient at 280 nm: 1.36 for a solution of 1 mg/ml, Johnstone, A. and Thorpe, R. (1988) “Immunoassays”. In: Johnstone, A. and Thorpe, R., Eds., Immunochemistry in Practice, 2th Edition, Blackwell Scientific Pub, London, 257-260.
• IgG molecule dimensions: 13.7 nm (width), 8.4 nm (height), Horng et al. 2008
• Distribution in the body: intra- and extravascular
• Immunological function: secondary response
• Structure: self-assembles into hexamers, which form two dimensional crystals in aqueous solution (Shinichiro et al. 2014, Nature Materials)
• Function: Activate mammalian complements 
• Binds to: Protein A or Protein G

Examples of techniques where IgG antibodies have been successfully used

• Preparation of affinity columns and affinity purifications
• Western Blot analysis 
• ELISA
• Biotinylation or labelling with fluorescein or other chromophores
• Rocket immunoelectrophoresis  
• Immunoprecipitation
• Immunogold labelling  
• Immunohistochemistry

Agrisera Secondary Antibodies bind to

Available immunoglobulins from various species in different purity grades

         
        

Further information

Recommended literature about IgG antibodies

• Using Antibodies: A Laboratory Manual, E. Harlow and D. Lane, 1999,
  ISBN: 0879695447; Publisher: Cold Spring Harbor Laboratory Press.
• Immunochemistry in Practice, A. Johnstone and R. Thorpe, 1988,
  ISBN:0-632-01723-6; Publisher: Blackwell Scientific Publications.