Protocol Online logo
Top : Forum Archives: : Immunology and Histology

Endotoxin quantification - (May/08/2001 )

I recently quantified endotoxin in some peptide:protein conjugates Ihave been using in an immunization protocol. Endotoxin was measuredusing a LAL based kit from BioWhittaker, which worked very well. Myquestion is this, does anyone know how to convert endotoxin values fromEU/ml (Endotoxin Units) to a weight (i.e ug/ml) ?

Thanks in advance...



Perhaps somebody can back me up on this, but I think that 1 ng of LPS corresponds to 1-10 EU. This conversion can be used to calculate ng/ml.

Also, which test are you using? I know that BW's kinetic test is somewhat of an industry standard but I have spoken with many researchers who are unhappy with the QCL-1000 test for reasons including false negatives an variabillity.

Best regards,




1EU is equal to 100pg



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.

More information regarding endotoxin and our endotoxin removal product EndoTrap you find here:

Yours Sincerely,