Fixation Buffer is useful for intracellular staining procedures in preparation of cells for staining intracellular cytokines or other proteins. Fixation Buffer is used to fix cells prior to permeabilization using Permeabilization Wash Buffer (10X) (Leinco Product No.: K144). Leinco Technologies fixation Buffer has been formulated with prescreened paraformaldehyde with low background, thus producing the greatest signal to noise ratio.