Biology Reference
In-Depth Information
2 nm
minor groove
major groove
B DNA form
Figure 12.2.
The double helical structure of B-DNA. One pitch represents
10 nucleotides which are composed of a single turn of DNA. See also Color
Insert.
the Watson-Crick model, base composition of DNA is not random,
total amount of G equals to the total amount of C, and similarly total
amountof A and T are equalbased on the complementary rule [1].
12.3 Natural Electronalytical Characterictics of DNA
The electroactivity of purine and pyrimidine bases were found by
Emil Palecek in 1958. While bases have electroactive properties
and they are able to receive reduction and/or oxidation, other
componentsofnucleicacidssuchassugarandphosphategroupsare
electroinactive (reviewed in Refs. 3-6). In these reviews, oxidation
parts of A and G [6] and reduction parts of A, C, and G [3-6] were
shown besides the effect of secondary structure of DNA on A and C
reduction signals at mercury electrode.
Carbon-based electrodes are less sensitive to changes in DNA
structure [4, 7, 8]. It was shown that G and A can be detected at
