Alpha 1 Antitrypsin Antibody Staining Protocol for Immunohistochemistry


Description: Alpha-1-antitrypsin is synthesised in the liver and is present in serum and tissue fluids where it acts as an inhibitor of proteases, particularly elastase. Its main function appears to be the neutralisation of elastase released by neutrophils during an inflammatory response. As a result, in alpha-1-antitypsin deficiency, any stimulus which activates neutrophils in the lung may result in uninhibited elastase-induced tissue destruction.


Primary Antibody

Name: alpha-1-Antitrypsin Antibody

Clone: Rabbit Polyclonal

Supplier: Novocastra Labs

Catalog Number: NCL-A1Ap

Dilution: 1:250 - 1:500 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: Incubator
Buffer/pH value: IHC-TekTM Proteinase K Solution (Cat# IW-1101)
Heat/Cool Temperature: 37 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 staining of macrophages
Images: Search image

Additional Information:
Tissue Type: Colon, tonsil
Fixation: Formalin-fixed paraffin sections, and acetone fixed frozen sections
Positive Control: Colon, tonsil
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


There is no need to perform antigen retrieval on acetone fixed frozen sections



1. Alpha-1-antitrypsin deficiency - Alpha-1 antitrypsin deficiency (A1AD) is an autosomal recessive disorder marked by abnormally low or no serum levels of alpha-1 antitrypsin in the blood.  It is the most common genetic cause of liver disease in children and of emphysema in adults


2. Callea F, Fevery J, De Groote J, Desmet VJ. Detection of Pi Z phenotype individuals by alpha-1-antitrypsin immunohistochemistry in paraffin-embedded liver tissue specimens. J Hepatol 1986; 2:389-401. PubMed Abstract.


3. Carlson J, Eriksson S. Chronic 'cryptogenic' liver disease and malignant hepatoma in intermediate alpha-1-antitrypsin deficiency identified by a Pi Z-specific monoclonal antibody. Scand J Gastroenterol. 1985; 20:835-842. PubMed Abstract.