Aptamer Discovery Kits
- What Are Aptamers?
- Biomarker Discovery & Diagnostics
- Cell-Tissue Targeting & Imaging
- Drug Discovery & Delivery
- Aptamer Discovery Kits
Discover what aptamers can do for you!
An aptamer is a small, single stranded nucleic acid molecule (RNA or DNA, modified or unmodified) that can bind a target with high specificity and affinity. Aptamers typically interact with their targets via secondary and/or tertiary structure, such as stem/loop bulges and G quartets. The formation of these structures is dependent on the primary nucleotide sequence of the aptamer. Unlike antibodies, most aptamers are raised in vitro by a PCR-based, iterative process known as SELEX, or Systematic Evolution of Ligands by Exponential Enrichment. SELEX ultimately isolates out favorable target-binding sequences from extremely diverse, randomized pools of aptamers.
This kit demonstrates the use of Melting Off SELEX, which is a selection strategy designed to produce structure-switching aptamers through a known and consistent mechanism. By using a constant region—either in the center of the library between two random regions, or towards one end of the library but downstream of the 5’ primer or upstream of the 3’ primer—it is possible to ‘capture’ the library onto a streptavidin-coated magnetic bead via a biotinylated oligo complementary to the constant region. This capture mechanism allows for bound and unbound structure-switching aptamers to be partitioned, because aptamer candidates that respond to target will have to change their structures and effectively ‘melt off’ of the complementary strand immobilized on the magnetic bead in order to bind. An appropriate number of rounds and the specific conditions of each round need to be determined in order to conduct a successful selection. Additionally, appropriate library and buffer/matrix parameters must be considered in order to plan out the specific conditions used during selection.
General considerations for targets/counter-targets: If the target is hydrophobic, consider using a hydrophobic buffer component (such as 10% ethanol or methanol) to facilitate library/target interactions. To reduce non-specific binding occurring from electrostatic interactions if there is a difference in the net charge of the target vs the counter-target, consider adding components to the counter selection to reduce the influence, like BSA which has a net negative charge. Counter selection is important for eliminating non-specific and weakly binding candidates.
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Aptamer Discovery Kit
The Aptamer Discovery Kit contains sufficient reagents for 12 rounds of selection and PCR amplification, including DNA library, Biotinylated Capture Probe, Magnetic Beads, Wash Buffer, and PCR Master Mix. Instruction Sheet