Blocking and Stabilizing in One Step
Blocking and Stabilizing in One Step
A common question assay developers may ask themselves: is it possible to block and stabilize a dried down protein in one step? Here at Surmodics™ IVD, the answer is yes! Surmodics™ IVD offers assay developers three options for blocking and stabilizing dried down proteins in one step. Surmodics™ IVD’s StabilCoat™, StabilBlock™ and StabilGuard™ offer assay developers the gold standard for stability and blocking efficacy. These dried protein stabilizers and blockers provide improved assay performance in a one-step process for streamlined manufacturing.
Surmodics™ IVD’s dried protein stabilizers and blockers preserve the conformation and activity of dried proteins coated on a wide range of surfaces, keeping antibodies and antigens at peak performance for long durations. At the same time, the blocking mechanisms in these reagents reduce non-specific binding of interfering proteins to maximize assay sensitivity.
Understanding Dried Down Proteins
Before understanding the mechanisms of dried protein stability and blocking, it is important to understand the fundamentals of what exactly is being dried down. Proteins are critical components when building protein-based immunoassays. Proteins are large molecules comprised of chains of amino acids. These proteins, mainly antibodies and antigens, play essential roles in immunoassay reactions.
In ELISA development, a dried down protein or capture antigen/antibody binds to the target and ultimately to the detection antibody. These binding events, in combination with a detection chemistry such as a TMB microwell substrate, provide the results of an immunoassay.
How to Stabilize a Protein
Proteins are prone to degradation. Even routine storage can be tough on proteins. It is essential that the protein is preserved in its natural state to prevent the dried-down protein from degrading over time. Therefore, it is important to find ways to increase the shelf life of these important components. A protein stabilizer is a versatile compound that will help these proteins last for longer periods of time.
Surmodics™ IVD’s dried protein stabilizers and blockers preserve the conformation and activity of dried down proteins coated on a wide range of surfaces, keeping antibodies and antigens at peak performance for long durations. In preserving the conformation and activity of dried proteins, these reagents help extend the shelf life of dried proteins on a variety of surfaces, including polystyrene plates, latex beads, magnetic particles, and nitrocellulose membranes.
Prolonging Shelf Life:Accelerated stability projections demonstrate at least 85% retained activity for greater than 2 years using Surmodics™ Immunoassay Stabilizers.Accelerated stability projections demonstrate at least 85% retained activity for greater than 2 years using Surmodics™ Immunoassay Stabilizers.
Graph Details: the accelerated stability tests used a rabbit polyclonal IgG ELISA assay to assess each stabilizer. Seventy-seven days of accelerated stability testing is equivalent to 2+ years of real-time stability.
How to Block a Protein:
When using dried down proteins or capture antigens/antibodies, the risk of cross-reactivity can be very high. Cross-reactivity and non-specific binding may be common issues assay developers experience when building immunoassays.
When choosing the antibody titration during assay optimization, assay developers need a variety of blocking mechanisms. Using the right blocker is imperative in building accurate and reliable immunoassays. The dried protein stabilizers and blockers from Surmodics™ IVD each have a distinct blocking mechanism that works to lessen any non-specific binding on the surface. Actually, here is where the dry protein stabilizers and blockers from Surmodics™ IVD differ.
The effectiveness or strength of each of these reagents' blocking varies. For this reason, Surmodics™ IVD advises comparing StabilCoat, StabilGuard, and StabilBlock side by side in order to determine which blocker is best for the requirements of each individual assay.
Lowering Non-Specific Binding: StabilBlock minimizes non-specific binding from the sample matrix and downstream assay components to enable lower detection limits.
Graph Details: A serum assay was constructed to demonstrate lower non-specific binding from the sample matrix. Mouse IgG was passively absorbed onto a plate and blocked. Human serum was incubated, washed and detected using an anti-human IgG (HRP) conjugate. Passive absorption of serum on the plate was quantified.
Non-specific binding
Mechanisms of Protein Stability & Blocking:
To learn more about Surmodics™ IVD’s specific recommendations for use visit the ELISA Solutions and Protocols page below. Additionally, each reagent has a specific product insert where assay developers can learn more about unique features and recommendations of use. Visit the links below for further information.
ELISA Assay Solutions & Protocols
Improved Assay Sensitivity:
Along with increased stability and reduced background noise comes improved sensitivity – another critical component in assay development! When assay developers use Surmodics™ IVD’s dried protein stabilizers and blockers, the result is increased signal-to-noise ratios across the assay range. Surmodics™ IVD’s three unique formulations provide assay developers a variety of options to optimize lower limits of detection.
How Surmodics™ IVD Can Help:
Surmodics™ IVD’s immunoassay reagents are all specifically designed to improve the performance of immunoassays. Specifically, our dried protein stabilizers and blockersshelp to improve the sensitivity, stability, and specificity of diagnostic applications. Free samples are available for evaluation.
Start your free evaluation today!For further assistance, please contact the team to connect directly with one of Surmodics™ IVD’s R&D scientists or visit the IVD Library to learn more about ELISA troubleshooting and optimization!
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