Neptune block

ICT’s Neptune Block Blocking Buffer is non-mammalian and designed primarily for antigen-down ELISA formats as well as sandwich assays with high background problems. This buffer is particularly useful when working with human and other mammalian serum samples as it works to reduce interactions between sample and blocking molecules.

Neptune Block utilizes a non-mammalian protein extract and small molecular stabilizers to provide a high degree of blocking efficiency. It is designed for antigen-down and antibody sandwich immunoassays with high background problems.

Neptune Block is a heterogeneous mixture of small molecules capable of blocking the unoccupied regions of the polystyrene plate wells that are not sterically accessible to larger, traditional mammalian blocking agents. This minimizes non-specific binding interactions and significantly reduces background noise, increasing the sensitivity of the assay. These small blocking molecules also stabilize the adsorbed proteins for improved retention of antigenicity or antibody activity after drying and long-term storage. In addition, the small size of these unique blocking agents results in minimal steric hindrance to key epitope regions of coated proteins, which prevents masking of small coated peptides, enhancing their specific antigenic signal.

Since Neptune Block utilizes a non-mammalian protein blocking agent, it is antigenically foreign to most mammalian immune systems. In antigen-down ELISA formats used to detect antigen-specific antibodies, this reduces the possibility of false-positives generated from endogenous antibodies in the sample reacting with plate blocking proteins.

Neptune Block is particularly useful when working with human, swine, and bovine serum samples, as minimal interaction between Neptune Block’s blocking molecules and mammalian serum matrices results in lower backgrounds.

Neptune Block contains an antimicrobial agent for room temperature blocking of the plate and for long-term storage of the dried plate at 2-8°C. When preparing plates, the antibody or antigen is typically coated using 50-200 µL of coating solution per well. After coating, plates are normally washed to remove unbound proteins and then blocked using a larger volume of blocking buffer than was used for coating, such as 300 µL per well. This ensures that all uncoated regions inside the well are blocked sufficiently.

Neptune Block is available in 100 mL, 500 mL, and 1 L sizes.
Bulk volumes and custom packaging are available upon request.

Neptune Block is also included in our Block Buffer Optimization Pack which provides five of ICT’s blocking buffer formulations for an economical approach to selecting the best blocking buffer formulation for an assay.


Neptune block


ICT provides all the components you need to build a better ELISA. ICT’s coating buffers, blockers, sample and assay diluents, conjugate stabilizers, and wash buffer all work together to minimize the build up of unwanted proteins to generate a very clean signal. These products work together to address common issues during ELISA development, such as specificity, sensitivity, reproducibility, and shelf-life. ICT’s ultimate goal is to help you develop optimized ELISAs that have a high specific signal and low background noise. If you need assistance in your assay development, or are looking for assay development services, please see our available services.


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