Toggle-SELEX is a sophisticated and powerful variant of the traditional SELEX process for aptamer development, specifically designed to generate aptamers that recognize multiple, closely related targets or a specific epitope common across different species/conditions. Let's break down what an Aptamer Screening Service using Toggle-SELEX entails, its applications, and what you should consider when selecting a service provider. What is Toggle-SELEX? The core idea of Toggle-SELEX is to "toggle" or alternate the selection pressure between two (or more) related target molecules during the SELEX rounds. Traditional SELEX: Uses a single target to evolve aptamers with high affinity for that specific target. It often negatively selects against related molecules (counter-selection) to ensure specificity. Toggle-SELEX: Actively uses two positive selection targets in an alternating pattern. For example: Round 1: Select against Target A (e.g., human protein). Round 2: Select against Target B (e.g., mouse ortholog of the same protein). Round 3: Back to Target A, and so on. Counter-selection against unrelated structures is still used to maintain general specificity. This process enriches for nucleic acid sequences that bind to a conserved structural epitope present on both targets, while sequences that bind to unique epitopes on only one target are filtered out. Key Applications of Toggle-SELEX This method is invaluable when you need cross-reactive or broad-spectrum recognition: Cross-Species Reactive Aptamers: Develop aptamers for preclinical research. For example, an…
