Molecular Biology DNA Library

Question: Discuss at least two different kinds of probes and how they can be used to screen libraries. Answer: The probes that are used to screen a DNA library are RNA or DNA fragments that detect the nucleotide sequences in a sample. One type of probe is Molecular bacons which are composed of 25 nucleotides. The five nucleotides at each end are complementary to each other and 15 nucleotides of the middle portion are complementary to the target DNA or RNA. The complementary base nucleotides with each other and the remaining 15 nucleotides bind with the target RNA or DNA. Another type of probes is Taqman probes are oligonucleotide probes with flurophore attached to its 5 end and quencher to the 3 end. The newly formed strand is synthesized by the Taq polymerase and it degrades the probe causing the flurophore to release. Thus the amount of a particular DNA template is determined from the number of flurophore released (Cui et al., 2012). References: Cui, L., Lin, X., Lin, N., Song, Y., Zhu, Z., Chen, X., Yang, C. J. (2012). Graphene oxide-protected DNA probes for multiplex microRNA analysis in complex biological samples based on a cyclic enzymatic amplification method.Chemical Communications,48(2), 194-196.