In this study lipopolysaccharide of Escherichia coli was extracted by hot phenol-water method as described previously with some modifications ,the bacteria was isolated from urinary tract infection . The endogenous pyrogen activity of extracted LPS was evaluated resulted in substantial increase of rabbits’ body temperature (mean: 1.6°C ).the effect of extracted LPS on immune parameters was studying in rabbits contain three rabbits in each group ,were injected Intramuscule (I.M.) Intravein( I.V.), I.M. & I.V. to give mean total protein 54.72,54.97,59.1 in Primary immune response,60.67,62.6,66.43 in secondary immune response respectivily and mean of C.R.P.in secondary immune response revealed inceasing more than mean in Primary immune response.
Keywords: Escherichia coli, phenol-water, rabbit, immunology.