Fecal contents are collected and weighed, then resuspended in PBS + 5% gelatin supplemented with a complete inhibitor cocktail. The samples are extracted with vortexing and prepared in a concentrated form to facilitate the detection of low levels of cytokines.
The insoluble fraction is separated by centrifugation at greater than 10,000xg for 10 minutes at 4°C. The resulting supernatants can be assayed immediately or frozen at -80°C.
It may be necessary to test an optimal dilution, using the extraction buffer as the assay matrix for standards and blanks.