Diffusely adhering Escherichia coli (DAEC) has been recognized as one of the six classes of diarrheogenic E.coli have been associated with persistent diarrhea in children older than infants. The only known virulence factors of DAEC strains are the adhesins belong to the Afa/Dr family are only virulence factors known of DAEC strains. In studies of case and control, made in Porto Velho, DAEC appeared the cause of diarrhea in 7.4% of the smaller children of 5 years old. The using the PCR diagnosis was not specific to delect DAEC satisfactorily and the adhesion assay in HEp-2 cells was the used to characterize the DAEC isolates. Observing the difficulties for samples detection the pathogenic, this research work had objective of producing a polyclonal serum for the sample identification of DAEC without the need for cellular culture, so that this serum can be used by clinical analyses laboratories, throughout the public health system. Search for fast diagnose to this enteropathogen, since serologic test do not exist. In this study the F1845 protein was predicted by a computer program and expressed in E. coli with the GST fusion expression system. The GST fusion or GST-F1845 protein was purified by EIA enzymatic immune assay and Gluthathione Sepharose A columm were used to confirm specificity of anti-F1845 a test was made to detect the antigen-antibody. The development of a quick test for the identification of DAEC is show to be important as a method of testing advantages of serological and aglutinization doesn?t exist. As the identification process by other methods is very expensive in both financial terms and time spend. The quick identification of this disease is essential for the correct treatment and consequent control of diarrheal disease associated with DAEC.