Endosomes are membrane-bound vesicles formed through the invagination of the plasma membrane. They are part of the endocytic membrane transport pathway from the plasma membrane to the lysosome and allow molecules to be sorted before reaching the lysosome. Molecules internalized at the plasma membrane can be transported to lysosomes for degradation, or recycled to the plasma membrane. Endosomes can also transport molecules originating from the Golgi on to lysosomes or recycle them back to the Golgi.

Endosomes are found in three forms: early endosomes, late endosomes, and recycling endosomes. The early endosomes develop into late endosomes, which then fuse with lysosomes. Each endosome form has distinct morphology and specific markers.

Endosomal marker antibodies detect proteins specific to endosomes and can aid in the study of the morphology and dynamics of the endosome. Endosomal marker antibodies can also help elucidate the role or roles a protein may play in a number of tasks that are centered in or influenced by the endosome. In addition, endosomal marker antibodies can track cell surface receptors that induce receptor-mediated endocytosis and are often studied as transporters of targeted delivery of enzymes, drugs, toxins, or DNA for therapeutic treatments. Quality Invitrogen endosomal marker antibodies are available for your research needs.

Endosomal marker antibody targets

  • ADRB1
  • AP2S1
  • APOA1
  • ATP1A
  • CAV1
  • CAV2
  • CD4
  • CFTR
  • CLTB
  • DDIT3
  • EEA1
  • EGFR
  • ERBB2
  • HLA-A
  • IGF2R
  • INS
  • MAPK1
  • RAB4A
  • RAB5A
  • RAB7A
  • TNF

Featured product data

Immunohistochemistry performed on normal biopsies of deparaffinized human pancreas tissue. To expose target proteins, heat-induced antigen retrieval was performed using 10 mM sodium citrate (pH 6.0) buffer, microwaved for 8–15 minutes. Following antigen retrieval tissues were blocked in 3% BSA-PBS for 30 minutes at room temperature. Tissues were then probed at a dilution of 1:200 with a mouse monoclonal antibody recognizing CFTR (Cat. No. MA1-935) or without primary antibody (negative control) overnight at 4°C in a humidified chamber. Tissues were washed extensively with PBST and endogenous peroxidase activity was quenched with a peroxidase suppressor. Detection was performed using a biotin-conjugated secondary antibody and SA-HRP, followed by colorimetric detection using DAB. Tissues were counterstained with hematoxylin and prepped for mounting.


Immunofluorescent analysis of CFTR using an antibody recognizing CFTR shows staining in WiDr colon carcinoma cells. CFTR staining (green), F-actin staining with Phalloidin (red), and nuclei with DAPI (blue) is shown. Cells were grown on chamber slides and fixed with formaldehyde prior to staining. Cells were probed without (negative control) or with or a CFTR monoclonal antibody (Cat. No. MA1-935) at a dilution of 1:100–1:200 overnight at 4OC, washed with PBS and incubated with a DyLight 488−conjugated secondary antibody (Cat. No. 35552 for GAR; Cat. No. 35503 for GAM). Images were taken at 60x magnification.


Western blot detection of caveolin-1 on rat heart protein extract using a caveolin 1 polyclonal antibody (Cat. No. PA1-064).


Annotated product references

Cat. No. MA1-935 was used in a blocking or activating experiment to study the mechanism for Salmonella enterica serovar Typhi adhesion with BHK epithelial cells. Bravo D, Blondel CJ, Hoare A et al. (2011) Type IV(B) pili are required for invasion but not for adhesion of Salmonella enterica serovar Typhi into BHK epithelial cells in a cystic fibrosis transmembrane conductance regulator-independent manner. Microb Pathog 51:373–377.

Cat. No. MA1-935 was used in immunohistochemistry and western blot to investigate the role of cystic fibrosis transmembrane conductance regulator in the rat endocrine pancreas. Boom A, Lybaert P, Pollet JF et al. (2007) Expression and localization of cystic fibrosis transmembrane conductance regulator in the rat endocrine pancreas. Endocrine 32:197–205.

Cat. No. PA1-064 was used in immunohistochemistry to investigate the involvement of androgen and oxytocin receptor in the pathogenesis of benign prostate hyperplasia. Sendemir E, Herbert Z, Sivukhina E et al. (2008) Colocalization of androgen binding protein, oxytocin receptor, caveolin 1 and proliferation marker p21 in benign prostate hyperplasia. Anat Histol Embryol 37:325−331.

Cat. No. PA1-064 was used in immunocytochemistry to investigate the involvement of the oxytocin receptor pathway in leiomyoma. Sendemir A, Sendemir E, Kosmehl H et al. (2008) Expression of sex hormone-binding globulin, oxytocin receptor, caveolin-1 and p21 in leiomyoma. Gynecol Endocrinol 24:105−112.