pcr prob

Sudheendra Rao N R via methods%40net.bio.net (by sudhee26 from gmail.com)
Tue Feb 26 00:06:25 EST 2008

Ethidium Bromide

1. EtBr interacts with DNA in more than one way=97intercalative and
electrostatic at low ionic strength, and semi-intercalative and
electrostatic at a higher strength of the solution. These results are in
good accordance with the ones obtained by spectroscopic (absorption and
fluorimetric) methods.

Differential pulse voltammetric studies of ethidium bromide binding to DNA.
Volume 68, Issue
January 2006, Pages 48-55

2. Both DNA and RNA compoents contribute to the induced dichroic elliticity=
Digestion of nucleoli by RNase or DNase shows that most of the induced
ellipticity comes from the DNA component. In nucleoli with an RNA/DNA =3D 0=
the RNA component gives only 20% of the total ellipticity when measured at
an ethidium bromide/DNA =3D 0.25. Spectro-fluorometric titration shows that
ethidium bromide intercalates mostly into DNA in nucleoli.

3. The binding of three ethidium derivatives, ethidium (1), des-3-amino
ethidium (2) and des-8-amino ethidium (3), to short (approximately 35 base
pairs), random sequence DNA has been investigated using 300 MHz proton NMR.
Removal of the amino group at position 3, but not at position 8, on the
parent ethidium shortens the lifetime of the intercalative state; this
implies that the 3-NH2 group is involved in stabilization of the drug-DNA
complex. Analysis of the drug-DNA spectra indicates that there is a
preference for binding of the drugs adjacent to G.C base pairs.

4. A discussion forum talking about the similar issue.

5. An Interesting problem at protocol online.

There is indeed no spoon ;)


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