Endotoxin in culture media - Endotoxin in culture media (Mar/09/2002 )
Hi. Does anyone know the acceptable level of endotoxin in endotoxin units (EU) per mL? I've just performed Sigma's E-Toxate LAL assay and the standards are expressed in EU/mL. All of the culture media specifications I've seen express endotoxin levels in ng/mL.
The acceptable level of endotoxin depends on which cells you are looking at, and how they respond to endotoxin.
The E-Toxate endotoxin standard is standardized against the US Reference Standard Endotoxin. The ratio RSE/E-Toxate standard gives the potency: around 10EU/ng.
For example, 100 pg of the standard endotoxin EC-5, 200 pg of EC-2 and 120 pg of endotoxin from Escherichia coli 0111:B4 have an activity of 1 EU.
It is taken as a rule of thumb that 1 EU corresponds to 100 pg of endotoxin.
Cell Type ng/mL
Macrophages and mononuclear phagocytes 0.01
Equine macrophages 0.5
Human IVF embryos 1
Aortic rings (Rat) 1
leukocyte cultures 1
murine macrophages 1
Aortic endothelium (Rabit) 10
Murine B lymphomas (i.e. 70Z/3) 10
Recombinant CHO 10
Cardiac myocytes (rat) 10
Porkine aortic endothelial cells 25
Human T Cells 100
bovine aortic endothelial cultures 100
Uretal epithelium 5000
Reference you find in the Endotoxin Compendium of Profos AG.
More information regarding EndoTrap, the endotoxin removal product from Profos AG, you find here: