Secondary Antibodies and Conjugates

KPL pioneered the production of large-scale affinity purification and offers a wide range of antibodies with defined specificities.  KPL’s polyclonal antibodies are obtained from the serum of goat or rabbit immunized with a particular antigen. The antiserum is affinity purified to remove nonspecific antibodies, increasing sensitivity and reducing background.  Further purification may be required to remove potential nonspecific reactivities among related animal species or to reduce shared reactivity with other heavy and light chains. For example, antibodies affinity purified against mouse IgG may recognize similar regions on human IgG if it is present in the same immunoassay. Therefore, KPL further adsorbs antibodies to mouse immunoglobulins against immobilized human serum.  For more information on KPL’s purification process, see our Technical Note, How KPL Purifies Its Antibodies. KPL’s affinity purified polyclonal antibodies are available unlabeled or labeled with enzymes, biotin or a variety of fluorochromes.  See chart below for an overview of our antibody product line. Please see our Antibody Selection Guide for assistance in choosing the appropriate antibody for your application.

F(ab’)2 Fragments 
F(ab’)2 fragments to immunoglobulins eliminate nonspecific binding between the Fc portions of antibodies and the Fc receptor on cells. They are available unlabeled or labeled with AP, HRP, biotin or fluorescein.


Applications of Secondary Antibodies

KPL’s secondary antibodies are ideal for use in immunoassay applications such as ELISA, immunoblotting and immunohistochemistry.  Affinity purified antibodies are especially valuable in immunoassays where extraneous serum proteins and unknown antibodies can interfere with test results. Affinity purified antibodies are useful as primary and secondary antibodies in heterogeneous immunoassays and make excellent secondary anti-species (e.g., Goat anti-human IgG) antibody conjugates. Antibodies directed to bacterial membrane or viral coat proteins recognize multiple antigenic determinants. Therefore, unlike monoclonal antibodies, affinity purified antibodies can be used as both the capture and detection antibody in capture "sandwich" immunoassay systems.  Our Antibody Application Guide provides information regarding the relative performance of KPL antibodies in various types of immunassays. For more detailed information, view our Technical Note, The Use of Antibodies in Immunoassays.


Stabilizers and Preservatives

Lyophilized enzyme-labeled antibodies and F(ab’)2-labeled antibodies contain goat serum and/or bovine serum albumin as protein stabilizers.  Rabbit antibodies contain rabbit serum.  No preservatives are added with the following exceptions:


·                  R-phycoerythrin-labeled antibodies contain a proprietary anti-bacterial agent.  

·                  Gold-labeled antibodies contain sodium azide (0.1%).

·                  Liquid antibodies contain proprietary preservatives and stabilizers for long-term storage at 2-8o C. 


See our list of frequently asked questions for additional support in using our products.

 Five Reasons To Choose KPL Antibodies and Conjugates

  • We make what we sell. As a pioneer we have produced purified antibodies for over 30 years!
  • High performance: high signal:noise, defined specificity, lot-to-lot consistency
  • Broad product offering: Antibodies to 20 animal species immunoglobulin, 17 different tags/labels
  • Quality: produced in our ISO 9001:2008 facility, KPL antibodies are used by leading research and biotech companies
  • Antibodies in stock! We maintain >98% availability of all our antibody products.
Alkaline Phosphatase-labeled Antibodies

Anti-FluorTag Antibodies and Conjugates

Biotin-labeled Antibodies

Cyanine Dye-labeled Antibodies

DyLight labeled Antibodies and Streptavidin

Fluorescein-labeled Antibodies (FITC)

Gold-labeled Antibodies

Horseradish Peroxidase-labeled Antibodies

Labeled Streptavidin

Rhodamine-labeled Antibodies (TRITC)

R-Phycoerythrin (RPE)-labeled Antibodies

Unlabeled Affinity Purified Antibodies