Aptamers are an emerging class of detection molecules that rival antibodies in diagnostic and therapeutic application [21]. Aptamers are single strands of DNA (ssDNA), RNA, and sometimes peptides, which have a high binding affinity and high specificity for molecular targets [25], as well as large cellular targets. This makes their application in molecular targeting very desirable. Aptamers can bind to a wide variety of targets, ranging from surface proteins on cancer cells (tenascin-C) [7], to the biological agents that cause Malaria [10] and anthrax [11]. Aptamers can also target small organic targets, such as Kanamycin A [1] and glucose [27]. Aptamers also have the ability to bind to very low epitope targets, with the help of modifications,
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From this pool, only the aptamers with an affinity for the target remain after a respective round. Because the amount of target added is less than the amount of library, the aptamers with a high affinity for the target outcompete the other aptamers with a lower affinity [27]. At the end of the entire process, only a few of the starting aptamers remain; those with the highest affinity for the …show more content…
This means, for different targets, different parts of the procedure can be changes, such as target incubation time. Some of these variations include adding a fluorescein modification to the aptamers (Flu-Mag SELEX) [5], using multiple libraries (Chimeric-SELEX) [22], and immobilizing the library on streptavidin beads (Capture-SELEX) [1]. The benefit of changing the SELEX process for a specific target is that it can allow for the more specific detection of the target. For example, the Capture-SELEX variant allows for an easier detection of pharmaceutical drugs and other small organic targets [1], because it immobilizes the library on streptavidin beads, which helps the library bind to more specific targets [27].This research used the Capture-SELEX variant (Figure 2), because the immobilization of the library on streptavidin beads allows aptamers to search for small organic molecules without any modifications to the target molecule. Since this research aimed to isolate aptamers for a specific and small target, the Capture-SELEX process was
From this pool, only the aptamers with an affinity for the target remain after a respective round. Because the amount of target added is less than the amount of library, the aptamers with a high affinity for the target outcompete the other aptamers with a lower affinity [27]. At the end of the entire process, only a few of the starting aptamers remain; those with the highest affinity for the …show more content…
This means, for different targets, different parts of the procedure can be changes, such as target incubation time. Some of these variations include adding a fluorescein modification to the aptamers (Flu-Mag SELEX) [5], using multiple libraries (Chimeric-SELEX) [22], and immobilizing the library on streptavidin beads (Capture-SELEX) [1]. The benefit of changing the SELEX process for a specific target is that it can allow for the more specific detection of the target. For example, the Capture-SELEX variant allows for an easier detection of pharmaceutical drugs and other small organic targets [1], because it immobilizes the library on streptavidin beads, which helps the library bind to more specific targets [27].This research used the Capture-SELEX variant (Figure 2), because the immobilization of the library on streptavidin beads allows aptamers to search for small organic molecules without any modifications to the target molecule. Since this research aimed to isolate aptamers for a specific and small target, the Capture-SELEX process was