Question

Why is the dye termination method considered better than chains termination technique? (Any two) Why is the autoradiogram read from bottom to top (anode to cathode)? Why do bacteria produce restriction enzymes and how do they protect their own DNA from its action?

Answer 1

Dye termination method is automated/ doesn't use radioactive isotopes so is safer/ uses single lane Agarose gels/fewer steps needed. 

An autoradiogram is read from bottom to top because for arriving at the original sequence from 3' to 5', every C is read as G, T as A, A as T and G as C as we arrive at the sequence from anode to cathode.

Bacteria produce restriction enzymes to restrict the multiplication of Phage genome. Bacteria protect their own DNA from phage action by methylation of its restriction site available in chromosomal DNA.