Reverse Complementary Oligonucleotides

Several groups have created multifunctional streptavidins with reversible linkers to solid surface. Scouten and Konecny [87] used an immobilized oligonucleotide to capture a biotinylated complementary oligonucleotide bound to streptavidin, which was free to react with biotinylated protein. A captured biotinylated antibody was released by denaturation of the duplex DNA by incubation at low ionic strength. Morris and Rany [88] reported the release of streptavidin bound to the 3 (but not the 5 ) end in an ATP-dependent helicase reaction. 

An azobenzene-modified oligonucleotide 5 -AAAXAAAA-3 [15, X is the residue having an azobenzene moiety in the side chain (Fig. 4A)] was prepared and further separated into two diastereomers (15a and 15b) based on the chirality of the stereogenic carbon atom of 15 by reversed-phase HPLC [53]. The melting temperature (7m) of the duplex of each diastereomer of 15 with its complementary oligonucleotide counterpart (5 -TTTTTTTT-3 ) was photoregulated by the trans-... 

Differential display is a method for identifying differentially expressed genes, using anchored oligo-dT, random oligonucleotide primers and polymerase chain reaction on reverse-transcribed RNA from different cell populations. The amplified complementary DNAs are displayed and comparisons are drawn between the different cell populations. 

The PCR is a three-step cyclic process that repeatedly duplicates a specific DNA sequence, contained between two oligonucleotide sequences called primers (154,155). The two primers form the ends of the sequence of DNA to be amplified and are normally referred to as the forward and reverse primers. The forward primer is complementary to the sense strand of the DNA template and is extended 5 to 3 along the DNA by DNA polymerase enzyme (Fig. 27). The reverse primer is complementary to the antisense strand of the DNA template and is normally situated 200-500 base pairs downstream from the forward primer, although much longer sequences (up to 50 kbase) can now be amplified by PCR. The process employs a thermostable DNA polymerase enzyme (such as the Taq polymerase from Thermus aqualicus BM) extracted from bacteria found in hot water sources, such as thermal pools or deep-water vents. These enzymes are not destroyed by repeated incubation at 94 °C, the temperature at which all double stranded DNA denatures or melts to its two separate strands (155). 

The first four oligonucleotides given in the table are self-complementary, and they form full duplex structures in biomolecular processes that are the reverse of melting. The last two oligonucleotides are only partially self-complementary. However, they share a common self-complementary core with the previous two entries in the table. The common core of these four oligonucleotides is given in bold letters in the table. 

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