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     Red: Control Antigen (100ng) Purple: Antigen (10ng), Green: Antigen (50ng) Blue: Antigen (100ng),    

  
  

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     Western blot analysis using His tag mAb against recombinant protein. lane 1 :(100 ng); lane 2 :(50 ng); lane 3 :(25 ng); lane 4 :(10 ng); lane 5 :(2.5 ng); (Expected MW is 50 kDa).    

  
  

His-tag antibodies are essential tools in molecular biology and protein research, primarily used to detect or purify recombinant proteins engineered with a polyhistidine (His) tag. The His-tag, typically a short sequence of 6–10 histidine residues, was introduced in the 1980s as an affinity tag due to its ability to bind metal ions like nickel or cobalt in immobilized metal affinity chromatography (IMAC). This property simplifies protein purification under native or denaturing conditions.

His-tag antibodies are produced by immunizing animals (e.g., mice, rabbits) with His-tagged proteins or synthetic peptides. These antibodies recognize the His-tag epitope with high specificity, enabling applications such as Western blotting, ELISA, immunofluorescence, and immunoprecipitation. Unlike IMAC-based purification, His-tag antibodies allow detection or capture of His-tagged proteins without requiring metal-coordinated interactions, making them versatile in diverse experimental conditions.

Both monoclonal and polyclonal His-tag antibodies are available. Monoclonal antibodies offer consistent specificity, while polyclonal versions may provide higher sensitivity due to multiple epitope recognition. A key advantage of His-tag antibodies is their compatibility with proteins from any host organism, as the His-tag is an artificial sequence. They are widely used in studying protein expression, localization, and interactions, particularly in systems where endogenous histidine-rich proteins are absent or minimal. Their reliability and broad applicability have solidified their role as a cornerstone reagent in proteomics and biotechnology workflows.