American Qualex


Avidin and Streptavidin each have four high-affinity biotin binding sites per molecule. The multiplicity of biotin binding sites per avidin/streptavidin molecule can be exploited as either a primary or secondary system for signal amplification in immunohistology, ELISA and immunoblotting.

American Qualex offers a complete line of high quality biotin and avidin/streptavidin reagents for maximum flexibility and utility in all applications.

Streptavidin reagents have several advantages over the avidin reagents for some applications. Streptavidin has an isoelectric point substantially different from the isoelectric point for egg white avidin, and therefore can be used for applications where the pH employed may limit the solubility of egg white avidin. Streptavidin also has the advantage of being a slightly smaller molecule than avidin, resulting in less steric hindrance in applications such as tissue staining.

Available products:

  • Avidin - Alkaline Phosphatase
  • Avidin - Beta-Galactosidase
  • Avidin - Fluorescein
  • Avidin - Glucose Oxidase
  • Avidin - Horseradish Peroxidase
  • Avidin - Rhodamine
  • Avidin - Texas Red
  • Avidin - Unlabeled
  • Avidin Antigen

  • Streptavidin - Alkaline Phosphatase
  • Streptavidin - Beta-Galactosidase
  • Streptavidin - Coated Plates
  • Streptavidin - Fluorescein
  • Streptavidin - Glucose Oxidase
  • Streptavidin - Horseradish Peroxidase
  • Streptavidin - R-Phycoerytherin
  • Streptavidin - R-Phycoerytherin
  • Streptavidin - Texas Red
  • Streptavidin - Unlabeled