CD68 Antibody Staining Protocol for Immunohistochemistry


Description: CD68 is a 110 kD transmembrane glycoprotein which is highly expressed in human monocytes and tissue macrophages. On the basis of DNA and amino acid sequence homology analysis, it is proposed that the CD68 antigen belongs to the lamp/Igp family of lysomal/plasma membrane shutting proteins that play a role in endocytosis and/or lysomal function.

Primary Antibody

Name: CD68 Antibody

Clone: PG-M1, Mouse anti-Human

Supplier: Dako

Catalog Number: M0876

Dilution: 1:200 using IHC-TekTM Antibody Diluent (Cat# IW-1000 or IW-1001) to reduce background and unspecific staining and serum blocking step is NOT needed.

Incubation Time/Temp: 60 min/room temperature

Antigen Retrieval
Device: IHC-TekTM Epitope Retrieval Steamer Set (Cat# IW-1102)
Buffer/pH value: IHC-TekTM Epitope Retrieval Solution (Cat# IW-1100)
Heat/Cool Temperature: 95-100 ºC/room temperature
Heat/Cool Time: 20 minutes/20 minutes

Detection Methods
Standard Method: ABC Method or LSAB Method
Enhanced Method: Polymeric Methods

Chromogen Substrate
Reagent: DAB
Incubation Time/Temperature: 1-3 minutes/room temperature

Reagent: Mayer's Hematoxylin
Staining Time: 30 seconds

Staining Pattern: Cytoplasmic
Images: Search image

Additional Information:
Species Reactivity: Human
Fixation: Formalin, B-5 or Bouin fixed paraffin embedded sections, or acetone fixed frozen sections
Positive Control: Bone marrow macrophages and mast cells, liver Kupffer's cells, lung macrophages, lymph node and tonsil germinal center macrophages
Negative Control: Omit primary antibody, isotype control, absorption control
Blocking: 2-5% normal serum to reduce unspecific background staining; 0.5-3% H2O2 to block endogenous peroxidase activity; avidin/biotin to block endogenous biotin activity if necessary


Not need to perform antigen retrieval for acetone fixed frozen sections



1. Kunisch E., et al (2003) Macrophage specificity of three anti-CD68 monoclonal antibodies (KP1, EBM11, and PGM1) widely used for immunohistochemistry and flow cytometry. Ann Rheum Dis. 63(7):774-84.


2. Caffo M., et al (2005) CD68 and CR3/43 immunohistochemical expression in secretory meningiomas. Neurosurgery. 57(3):551-7; discussion 551-7. PubMed Abstract


3. Li WV, et al (1996) Immunohistochemical characterization of mast cell disease in paraffin sections using tryptase, CD68, myeloperoxidase, lysozyme, and CD20 antibodies. Mod Pathol. 9(10):982-8. PubMed Abstract