SignalFlex™ Antibody Conjugates

At CST, scientists make over 95% of our antibodies in-house. Because we control our antibody manufacturing process and rigorous conjugation procedures in-house, our scientists ensure that every lot of a SignalFlex conjugate is consistently made, purified, and biophysically characterized to match the integrity and quality of the previous lot. Using Size Exclusion Chromatography (SEC), we assess the purity of the antibody-dye conjugate of each lot, ensuring free antibody and dye have been removed. Every SignalFlex conjugate is manufactured to the same specifications:

• 200 μg/ml concentration
• 50 μg size
• With a pre-selected degree-of-labeling (DOL) (based on testing and optimization conditions for each specific dye)
  

Example SEC Data

Analytical size exclusion analysis of multiple lots of Rabbit (DA1E) mAb IgG XP^® Isotype Control conjugated to Pacific Blue™ dye. The orange line indicates Lot A, and the blue line indicates Lot B. The data demonstrate how CST methods optimize bio-conjugation chemistries and use stringent purification that removes free dye from the conjugate, resulting in a highly consistent final product.

SignalFlex conjugates are similar in that they are manufactured using the same high-quality standards and specifications as our other off-the-shelf CST antibody conjugates. They are tested via SEC, purified, and biophysically characterized to ensure lot-to-lot consistency. However, they are not tested in specific applications to determine performance or optimal dilutions. Therefore, researchers must determine the optimal dilutions and concentrations for their specific assay. We always recommend using a conjugated isotype control at the same concentration as the antibody conjugate in your experiments. SignalFlex conjugates are made on demand from the moment you place your order. They ship to you in 10 days or less.

Our off-the-shelf antibody conjugates are made in large lots and stored in our inventory, so they are ready to ship to you within a day. These standard off-the-shelf conjugates have been validated in specific applications to evaluate their performance and determine the optimal dilutions for their use in specific protocols. The optimal dilution range for the approved application can be found on the specific product’s datasheet.

Both SignalFlex and custom-ordered conjugates are made after purchase order and are manufactured using the same high-quality standards and methods as off-the-shelf CST conjugated antibodies. But every SignalFlex conjugate is manufactured to the same specifications: 

• 200 μg/ml concentration
• 50 μg size
• In PBS (pH 7.2) with > 0.1% sodium azide, and 2 mg/ml BSA
• With a pre-selected DOL (based on testing and optimization conditions for each specific dye)

Similar to other off-the-shelf CST catalog reagents, SignalFlex conjugates can be ordered online using standard methods. Custom-ordered conjugates are made according to your specific requirements (concentration, buffer, degree-of-labeling (DOL), etc.) and must be ordered with a quote and the assistance of your local account manager. Before ordering a custom conjugated antibody, be sure to see our tiered service options and learn more about our Custom Conjugation & Labeling Services.

Researchers need to perform individual application testing to determine the optimal antibody concentration and dilution in their assay when using SignalFlex and custom-ordered conjugates. For custom-ordered conjugates, application testing before shipment may be available for limited services and applications (for an additional cost).  

SignalFlex conjugates are manufactured on demand, specifically for your order. This allows us to offer a wider range of dye conjugate combinations while expediting the delivery process. SignalFlex conjugates are produced using the same high-quality standards and specifications as our off-the-shelf CST conjugates. However, they are not tested in specific applications to determine optimal concentrations or evaluate performance prior to shipping. Researchers must perform their own application-specific testing to optimize experimental conditions and ensure the most accurate results for their unique immunoassay.

The best concentration of SignalFlex antibody conjugate will vary depending on the application and the sample or model system used. Researchers should first test multiple titrations of the SignalFlex conjugate to determine the optimal concentration in their assay. When performing flow cytometry, we always recommend using an isotype control conjugate at the same concentration as the primary antibody conjugate.

Compatible isotype controls are available in our off-the-shelf CST catalog. Choose an isotype control with the same dye as the SignalFlex conjugate(s) you use.

Expert CST conjugation scientists selected a DOL that is within the range of likelihood to be optimal based on specific dye properties and historical data for CST antibody conjugates using the same dye.

Although SignalFlex conjugates have not been tested in specific applications, it is helpful to review the applications that the unconjugated parent antibody, and similar conjugates of the same antibody clone, have been approved for via validation testing. Not all SignalFlex conjugates will work in every application for which the parent antibody clone has been approved. Various factors may influence whether an antibody conjugate will work well in a particular application, including the brightness of the dye, whether amplification of a secondary antibody is needed, and so on. Application-specific testing needs to be performed by the end user in their own experimental system.

Please note that all fluorophore dyes offered by CST are compatible with flow cytometry experiments, but their compatibility may be influenced by the setup of your flow cytometer (lasers, filters). For imaging-based applications and experiments, fluorophore compatibility may be more limited due to the narrower range of fluorescent detection for microscopy and HCA platforms. To better understand the compatibility of excitation and emission properties of your fluorescent dye of interest, please use the Fluorescence Spectra Viewer.

Use the Fluorescence Spectra Viewer to view and better understand the excitation and emission properties of your fluorescent dye of interest, and how it may be compatible with your experimental conditions.

We have several tools that may be helpful when designing your panel. These include:

• Fluorescence Spectra Viewer
• Flow Cytometry Panel Builder
• Protocol Compatibility Table for Immune Signaling and Phenotyping by Flow Cytometry

In addition, you can find links to pertinent blogs, videos, webinars, and more on our Learn & Support page.

Please reach out to our Technical Support Team for guidance and support. Our expert scientists would be happy to assist you.

Our off-the-shelf and SignalFlex conjugate catalogs continue to grow. While new off-the-shelf antibody conjugates are added weekly and new SignalFlex conjugates are added approximately every 3-6 months, we understand you might need a solution sooner. If you don't see your desired antibody-dye combination right now, please don't hesitate to reach out to our Technical Support Team members, who are ready to assist you. They may be able to provide insights into upcoming releases or suggest readily available alternatives that may work for your panel.

For a truly tailored solution, please view our tiered options for Custom Conjugation & Labeling Services. You can also feel free to contact our Custom Conjugation Service Team to ask about custom conjugation services to meet your exact specifications.

We are unable to accept cancellations for SignalFlex conjugate orders once they have been placed. This is due to the fact that production begins immediately after your order has been submitted.

You can order more than 50 μg of your SignalFlex conjugate by purchasing multiple vials of the product. If your project requires a large amount from a single manufacturing lot, your local account manager can assist you with a bulk order.