Oligodeoxynucleotides isolation

Finally a few sentences are deserved for the vast area of DNA photochemistry. Thymine dimerization is the most common photochemical reaction with the quantum yield of formation in isolated DNA of all-thymine oligodeoxynucleotides 2-3% [3], Furthermore, a recent study based on femtosecond time-resolved transient absorption spectroscopy showed that thymine dimers are formed in less than 1 ps when the strand has an appropriate conformation [258], The low quantum yield of the reaction in regular DNA is suggested to be due to the infrequency of these appropriate reactive conformations. 

Suzuki, T., Yamaoka, R., Nishi, M., Ide, H., and Makino, K. (1996) Isolation and characterization of a novel product, 2 -deoxyoxanosine, from 2 -deoxyguano-sine, oligodeoxynucleotide, and calf thymus DNA treated with nitrous acid and nitric oxide. J. Am. Chem. Soc., 118, 2515-2516. 

Fig. 1. DNA was isolated from 11 F2 individuals segregating from a cross of two Glycine max (soybean) culdvars (A and B). Each DNA sample was amplified with a single 10-mer oligodeoxynucleotide primer (5 -AGCXntjTCTG). The amplification products were separated by electrophoresis in a 1.4% agarose gel and visualized by staining with ethidium bromide. The anows at the right of the gel point to polymorphisms between parents A and B that are segregating in the F2 generation. The mol-wt standards at the left of the gel are from a Hae ni digest of 0X 174 DNA.

Stationary phase. The classical example of a mixed mode column packing material is the low-pressure resin RPC-5 (13). It consists of non-porous Plaskon or Teflon particles to which aliphatic quaternary ammonium salts are adsorbed. RPC-5 has been applied successfully to the separation of tRNAs. tRNA fragments and more recently to the isolation of restriction fragments (14). RPC-5 itself is not commercially available. A RPC-5 analogue, however, has been developed, NACS, which can be purchased from BRL. NACS-12 has been used for mixed mode HPLC of DNA, DNA fragments and synthetic oligodeoxynucleotides. 

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