1. What Are Aptamers? Aptamers are short, single-stranded DNA or RNA oligonucleotides (typically 20-80 bases) that fold into specific 3D structures, allowing them to bind to target molecules (like hormones) with high affinity and specificity, similar to antibodies. They are often called "chemical antibodies." 2. Why Target Hormones with Aptamers? Hormones are critical signaling molecules (e.g., insulin, cortisol, thyroid hormones, estradiol, adrenaline). Aptamers against them offer unique advantages: High Specificity: Can distinguish between structurally similar hormones (e.g., T3 vs. T4). Synthetic & Reproducible: Produced chemically with minimal batch-to-batch variation. Stability: More thermally stable than antibodies. Modifiability: Can be easily labeled with fluorescent dyes, quenchers, or nanoparticles for detection. Low Immunogenicity: Ideal for in vivo diagnostic or therapeutic applications. 3. Core Components of the Screening Service A full-service provider would typically offer the following pipeline: a. Design & Library Construction: Use of a vast random oligonucleotide library (10^14 - 10^15 unique sequences). Customization of library design based on hormone properties (small molecule vs. peptide/protein). b. SELEX Process (The Core Screening): This is an iterative, in vitro selection process. Incubation: The library is exposed to the target hormone (immobilized or in solution). Partitioning: Unbound sequences are washed away; bound sequences (aptamer candidates) are retained. Elution & Amplification: Bound sequences are eluted and amplified by PCR…
