Rhodnius prolixus is a hemipteran haematophagous of the family Reduviidae, popularly known as "kissing bug ". It doesn't have preferential host, they feeds in any vertebrate of hot blood, besides the man. This insect is intermediate host of Tripanossomatidae, and pointed as principal vector of Chagas`s disease in countries as Venezuela and Colombia. The importance and the physiological role of midgut in lipid metabolism has been studied in different insect species. In Rhodnius the capacity of midgut loading the insect main lipoprotein, the lipophorin with lipids. Lipid rafts are cholesterol-enriched microdomains that are detergent-resistant at low temperatures and are involved in a number of cellular processes such as endocytosis, trafficking and cell signaling. The objective of this work is the purification and characterization of lipid rafts to define their role on lipophorin lipid transfer. Sucrose density centrifugation is the standard method for lipid rafts isolation. One hundred Rhodnius prolixus males were dissected, the midguts were removed, lysed, homogenized and incubated at 4°C in 1% Triton X-100. After 30 minutes the homogenate was subjected to a sucrose gradient. The lipid raft was localized in fraction 5 and 6 of sucrose density gradient. Protein content was measured by Lowry. Cholera toxin B subunit (CTB) is a specific ligand for ganglioside GM1 and can be used for the detection of GM1 containing microdomains. In order to investigate the presence of GM1, the fractions were submitted to a dot-blot using cholera toxin. The raft containing fractions were subjected to lipid extraction and TLC. The spots were analyzed by densitometry.