To whom working with DNA sequencing

[roniadam]

1. Would a primer extension reaction in DNA sequencing work using an RNA polymerase? any one can explain this point please?
2. When the products of a DNA sequencing reaction are separated by electrophoresis, why is it normally only possible to read about 500 to 800 bases, yet the sequencing reaction continues for thousands of bases?

[canalon]

1- look up initiation of the reaction for both enzymes. besides think about RNA stability.
2- think about the termination mechanism and the relation between probability of synthesis of a fragment of increasing length and the intensity of the signal.

[roniadam]

Still cannot find the answers

[canalon]

read this, and notably paragraph 3.1:

http://en.wikipedia.org/wiki/Rna_Polymerase