Help & FAQs: Secondary Antibodies

  • Are secondary antibodies for western blotting compatible with the Odyssey Imaging System (from LI-COR) available in your catalogue?
  • Our sister brand, Novus Biologicals, has several secondary antibodies compatible with the Odyssey Imaging System (from LI-COR). Here are the links:
  • Is there a recommended dilution in western blotting for HRP-conjugated secondary antibodies,  when a more potent chemiluminescent substrate, such as SuperSignal West Pico PLUS Chemiluminescent Substrate, is used? 
  • For the standard sensitivity substrate, we use 1:1000-1:2000 dilution of the HRP-conjugated secondry antibody. Higher sensitivity substrates might require higher dilutions. 1:2000-1:5000 dilution is a good place to start. 
  • What is a direct ELISA?
  • In a direct ELISA, a plate is coated with the analyte of interest and a labeled detection antibody is used to verify the presence of the analyte. The direct ELISA may use a colorimetric, chemiluminescent, or fluorescent reporter.
  • What is R&D Systems doing to reduce its use of packaging from non-renewable resources?
  • Environmental stewardship is important to R&D Systems and its employees. R&D Systems is ISO 14001:2015 Certified and as part of this we are continuously reviewing our sustainability practices and "green" options. First and foremost, the energy expended to ship back the styrofoam box is more detrimental to the environment than having the facility re-use or recycle it. Our stance is to encourage our customers to implement a recycling program locally. At R&D Systems we have chosen to reduce the use of styrofoam as much as possible by: doing extensive stability testing in order to determine which products can be shipped with minimal packaging at ambient temperatures, converting the use of non-recyclable packaging materials to recyclable plastics, cardboard, or biodegradable materials, and continuing to investigate alternatives to dry ice shipments, the use of re-usable containers, and gel packs that allow for smaller styrofoam containers. Employees were key to initiating a recycling program at our facilities. Internally, we recycle paper, plastic, cardboard, aluminum, and glass.
  • What is the expiration of R&D Systems proteins and antibodies?
  • R&D Systems has established a policy of not limiting the useful life of a product by providing an expiration date or manufacture date for our protein and antibody products. Under proper storage conditions, proteins and antibodies tend to be stable for many years. These conditions include storing proteins as lyophilized powder, storing the product frozen (-20° C or -80° C) at protein concentrations of greater than 0.1 mg/mL, and limiting the number of freeze/thaw cycles. Please see individual product datasheets for specific instructions. Routine quality control testing by our company ensures that all products have acceptable biological activities at the time of sale. R&D Systems can not control storage conditions of a product upon receipt by the end user. In lieu of an expiration date, we choose to offer a warranty on our protein and antibody products. All products supplied by R&D Systems are warranted to meet or exceed our published specification when used under normal conditions in your laboratory.Typically, this warranty will extend 6-12 months from time of purchase. Please see individual datasheets for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued.  For details regarding our warranty  please see
  • Will trehalose affect my conjugation reaction?
  • It is possible that the presence of trehalose will interfere in the successful conjugation of a protein. This will depend on the method used, and the customer should investigate this potential prior to purchasing the product.
  • Will trehalose affect the performance of the protein or antibody in my specific application?
  • We have seen no adverse effect in our bioassays or other approved applications. However, customers are advised to run a control in their assay to determine if the concentration of trehalose in the protein or antibody formulation has any adverse effects.
  • What is trehalose and why is it in the formulation?
  • Trehalose is a non-reducing sugar and does not react with amino acids or proteins as part of the Maillard reaction. It is found in nature in many plants and animals. Trehalose is an effective sugar for stabilizing proteins against damage caused by freezing. It can also make the protein more resistant to moisture when lyophilized, resulting in a product that is less likely to precipitate when reconstituted.
  • Will trehalose included in the formulation affect the animal if it is injected?
  • Trehalose is unlikely to have an effect in vivo. It has been approved as an excipient for use in human injectable drugs.The trehalose used by R&D Systems is derived from Saccharomyces cerevisiae and is determined to be at minimum 98.5% pure by HPAE. 

Secondary Antibodies