The Effect Of Non-Specific Interactions On Biomolecular Detection And Analysis

Non-specific interaction is a very important issue to be concerned in biomolecular detection and analysis, because such interactions can cause false positive results and other interference to the assay. In previously developed bioanalytical techniques, a commonly used solution is to eliminate or minimize non-specific binding by washing. The binding affinity of non-specific interactions is typically weak. After a few cycles of washing, molecules that are bound non-specifically to the immunoprobes can be eliminated. Another important approach to deal with non-specific interactions is to conduct strict control experiments to determine the specificity of the analytical results.

Even though non-specific interaction is an issue of concern, the reasons that cause the non-specific interactions are often unclear. Because NanoDLSay is a homogeneous solution assay, and no washing cycle is used to separate the assay product from the assay solution, there may be concerns on the specificity of NanoDLSay. Is the specificity of NanoDLSay worse than the existing techniques?

To answer this question, let’s first take a look at ELISA and Co-IP (co-immunoprecipitation). From extensive experience and observations, it is generally believed that the non-specific interactions are more significant in Co-IP than in ELISA. Both techniques use multiple washing cycles to reduce the non-specific binding. What then is the real reason behind the difference between these two techniques and why does Co-IP tend to have stronger non-specific interaction effect?