All products derived from donkeys were produced from the sera of domestic (US) and Mexican donkeys of a genus and species not protected by CITES. No CITES permit is required for the transportation of these materials.

The answer is yes, but with some precautions. One problem we have observed with using antibodies from one company and standard from another company is that there can be differences in immunological recognition (or the binding between antibody and recombinant protein). This can happen if there is a difference in the folding or sequence of the recombinant protein used as the standard vs. the recombinant protein used as the immunogen for the antibody. Protein folding or sequence differences in the antibody-binding region can lead to poor, or no, recognition of the standard.

If you do not see a specific application listed on our data sheet and R&D Systems has no further in-house data, Technical Service can check their reference database to see if any other researchers have published this use, sample type, and/or species with a specific product.

R&D Systems matched antibody pairs are a do-it-yourself immunoassay type product. R&D Systems has demonstrated that the two antibodies can be used in a sandwich immunoassay to recognize the recombinant protein. We recommend that the investigator have expertise in immunoassay building before attempting to use these products. Each investigator must empirically determine the optimal concentrations for the capture and detection antibodies. Amounts of antibodies supplied are not normalized to give the same number of plates. R&D Systems recombinant cytokines are not calibrated by ELISA and therefore must be mass calibrated by ELISA before use.

The grade of the BSA used has been found to be a critical component for running a successful ELISA. We suggest the a BSA with a minimum purity of 98% such as Catalog # 82-045 from Serological Proteins. Additionally, we now offer the same BSAs used in development of the DuoSet as accessory reagents. DY995 Reagent Diluent Concentrate 2 5 x 21 mL vials DY997 Reagent Diluent Concentrate 1 1 x 21 mL vial Refer to package insert for selection of the appropriate Diluent Concentrate or contact Technical Service.

R&D Systems does not epitope map its antibodies. The antibody is usually generated using the entire immunogen listed on the data sheet. If a peptide immunogen is used, this will be indicated on the datasheet.

Polyclonal antibodies generally have multiple epitope recognition. The antibodies are often generated using the entire immunogen stated on the product datasheet as both the immunogen and, in many cases, the affinity ligand for purification. If a peptide immunogen is used, this will be stated on the product datasheet.

In a direct ELISA a plate is coated with the analyte of interest and a detection antibody is used to verify the presence of the analyte of interest. This is only considered a semi-quantitative technique when compared with a recombinant standard. The direct ELISA uses the method of directly labeled antibody. Microwell plates are coated with a sample containing the target antigen, and the binding of labeled antibody is quantitated by a colorimetric, chemiluminescent, or fluorescent end-point.

A sandwich ELISA uses an immobilized capture antibody specific for the analyte of interest in a sample. The analyte of interest is then bound to the immobilized antibody. A labeled secondary antibody, specific for the analyte of interest, is used for detection. The analyte of interest is "sandwiched" between the two antibodies. Values are quantitative when compared with a standard curve.

Environmental stewardship is important to all of the employees at R&D Systems. R&D Systems has actively looked into "green" options several times over the past 20 years or more. First and foremost the energy that it takes to ship back the Styrofoam box is more detrimental to the environment than having the facility re-use it or recycle it locally. In light of that information, we have chosen to reduce the use of styrofoam as much as possible by: 1) Doing extensive stability testing in order to determine which products can be shipped with minimal packaging at ambient temperatures. 2) Converting the use of non-recyclable plastic or Styrofoam packaging material to cardboard, or recyclable or biodegradable materials. 3) Continuing to investigate the 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, glass and Styrofoam. We feel the environmental impact of having recyclable materials returned for reuse is much greater than our current practice. We feel it is best to encourage our customers to implement a recycling program locally and we can identify a recycling center for Styrofoam nearest their facility.

AB### designated antibodies are polyclonal antibodies that are purified using Protein A, Protein G or Ion Exchange chromatography. Refer to product insert. Consequently, the resulting purified antibody is a total IgG fraction. AF### designated antibodies, are antigen affinity chromatography purified and then further purified by ion exchange or size exclusion. Therefore AF### antibodies are IgG specific only to the antigen, whereas AB### designated antibodies may contain IgG not specific for the analyte of interest. Antibodies that have the designation MAB### are monoclonal antibodies. BAF### and BAM### designated antibodies are the biotinylated versions of the AF### and MAB### designated antibodies, respectively.

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 inserts 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 product inserts for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued. Details of our Warranty are stated on our Company Web site or in the Product Catalog.

An IgG protein is comprised of two heavy chains that are approximately 55 kDa each and two light chains that are approximately 25 kDa each for a total molecular weight of approximately 160 kDa.

- Protection of proteins during freezing and dehydration - Non-reducing - Remain amorphous during lyophilization - Has been used in approved parenteral therapeutics

Trehalose is a non-reducing sugar (MW 342.1) and, therefore, 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 has been reported to be one of the most effective sugars for stabilizing proteins against damage caused by freezing. Trehalose makes the protein more resistant to moisture gain when lyophilized, resulting in a product that is less likely to precipitate when reconstituted.

For years we have recommended ELISA plates from Costar (catalog #2592). These plates are now sold as an accessory to the DuoSet line. We offer both clear and black microtiter plates along with plate sealers. DY990 Clear 96-well polystyrene microplates 25/pack DY991 Black 96-well polystyrene microplates 25/pack DY992 Plate Sealers 100/pack For added convenience, try EvenCoat, goat anti-mouse IgG microplates, Catalog # CP001 & CP002. EvenCoat goat anti-mouse IgG microplates are clear, pre-blocked 96-well polystyrene microplates coated with goat-derived antibody specific for the Fc region of mouse IgG. These plates may be used as a solid support for most sandwich ELISAs utilizing a mouse IgG capture antibody and a non-mouse IgG detection antibody. Other applications include competitive ELISA, IgG isotyping, and hybridoma screening/selection. EvenCoat Microplates may be used with most DuoSet ELISA Development Kits. Check your DuoSet product insert to see if it can be used with EvenCoat Microplates. If there is no indication that it has been tested, please contact our Technical Service department for more information.

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 prior to purchasing the product.

Unlikely, it has been approved as an excipient for use in human injectable drugs. The trehalose used by R&D Systems is derived from Saccaromyces cerevisiae and is >98.5% pure by HPAE.

We do not know how it will affect all potential applications. We have seen no adverse effect in our bioassays or other approved applications. Customers are advised to run a control in their assay to determine if the concentration of trelahose in the cytokine or antibody has any adverse effect.

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 inserts 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 product inserts for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued. Details of our Warranty are stated on our Company Web site or in the Product Catalog.

The answer is yes, but with some precautions. One problem we have observed with using antibodies from one company and standard from another company is that there can be differences in immunological recognition (or the binding between antibody and recombinant protein). This can happen if there is a difference in the folding or sequence of the recombinant protein used as the standard vs. the recombinant protein used as the immunogen for the antibody. Protein folding or sequence differences in the antibody-binding region can lead to poor, or no, recognition of the standard.

If you do not see a specific application listed on our data sheet and R&D Systems has no further in-house data, Technical Service can check their reference database to see if any other researchers have published this use, sample type, and/or species with a specific product.

R&D Systems does not epitope map its antibodies. The antibody is usually generated using the entire immunogen listed on the data sheet. If a peptide immunogen is used, this will be indicated on the datasheet.

In a direct ELISA a plate is coated with the analyte of interest and a detection antibody is used to verify the presence of the analyte of interest. This is only considered a semi-quantitative technique when compared with a recombinant standard. The direct ELISA uses the method of directly labeled antibody. Microwell plates are coated with a sample containing the target antigen, and the binding of labeled antibody is quantitated by a colorimetric, chemiluminescent, or fluorescent end-point.

A sandwich ELISA uses an immobilized capture antibody specific for the analyte of interest in a sample. The analyte of interest is then bound to the immobilized antibody. A labeled secondary antibody, specific for the analyte of interest, is used for detection. The analyte of interest is "sandwiched" between the two antibodies. Values are quantitative when compared with a standard curve.

AB### designated antibodies are polyclonal antibodies that are purified using Protein A, Protein G or Ion Exchange chromatography. Refer to product insert. Consequently, the resulting purified antibody is a total IgG fraction. AF### designated antibodies, are antigen affinity chromatography purified and then further purified by ion exchange or size exclusion. Therefore AF### antibodies are IgG specific only to the antigen, whereas AB### designated antibodies may contain IgG not specific for the analyte of interest. Antibodies that have the designation MAB### are monoclonal antibodies. BAF### and BAM### designated antibodies are the biotinylated versions of the AF### and MAB### designated antibodies, respectively.

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 inserts 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 product inserts for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued. Details of our Warranty are stated on our Company Web site or in the Product Catalog.

An IgG protein is comprised of two heavy chains that are approximately 55 kDa each and two light chains that are approximately 25 kDa each for a total molecular weight of approximately 160 kDa.

All products derived from donkeys were produced from the sera of domestic (US) and Mexican donkeys of a genus and species not protected by CITES. No CITES permit is required for the transportation of these materials.

The answer is yes, but with some precautions. One problem we have observed with using antibodies from one company and standard from another company is that there can be differences in immunological recognition (or the binding between antibody and recombinant protein). This can happen if there is a difference in the folding or sequence of the recombinant protein used as the standard vs. the recombinant protein used as the immunogen for the antibody. Protein folding or sequence differences in the antibody-binding region can lead to poor, or no, recognition of the standard.

If you do not see a specific application listed on our data sheet and R&D Systems has no further in-house data, Technical Service can check their reference database to see if any other researchers have published this use, sample type, and/or species with a specific product.

Polyclonal antibodies generally have multiple epitope recognition. The antibodies are often generated using the entire immunogen stated on the product datasheet as both the immunogen and, in many cases, the affinity ligand for purification. If a peptide immunogen is used, this will be stated on the product datasheet.

In a direct ELISA a plate is coated with the analyte of interest and a detection antibody is used to verify the presence of the analyte of interest. This is only considered a semi-quantitative technique when compared with a recombinant standard. The direct ELISA uses the method of directly labeled antibody. Microwell plates are coated with a sample containing the target antigen, and the binding of labeled antibody is quantitated by a colorimetric, chemiluminescent, or fluorescent end-point.

A sandwich ELISA uses an immobilized capture antibody specific for the analyte of interest in a sample. The analyte of interest is then bound to the immobilized antibody. A labeled secondary antibody, specific for the analyte of interest, is used for detection. The analyte of interest is "sandwiched" between the two antibodies. Values are quantitative when compared with a standard curve.

AB### designated antibodies are polyclonal antibodies that are purified using Protein A, Protein G or Ion Exchange chromatography. Refer to product insert. Consequently, the resulting purified antibody is a total IgG fraction. AF### designated antibodies, are antigen affinity chromatography purified and then further purified by ion exchange or size exclusion. Therefore AF### antibodies are IgG specific only to the antigen, whereas AB### designated antibodies may contain IgG not specific for the analyte of interest. Antibodies that have the designation MAB### are monoclonal antibodies. BAF### and BAM### designated antibodies are the biotinylated versions of the AF### and MAB### designated antibodies, respectively.

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 inserts 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 product inserts for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued. Details of our Warranty are stated on our Company Web site or in the Product Catalog.

An IgG protein is comprised of two heavy chains that are approximately 55 kDa each and two light chains that are approximately 25 kDa each for a total molecular weight of approximately 160 kDa.

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 inserts 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 product inserts for specific stability claims. If the product fails during the stated period, a replacement product or credit will be issued. Details of our Warranty are stated on our Company Web site or in the Product Catalog.