Below is a restriction map of a plasmid Match the lane up wi

Below is a restriction map of a plasmid. Match the lane up with the enzyme used to digest the intact, circular plasmid.

1) Lane 1 =

a) HindIII

b) EcoRI

c) EcoRI and SacI

d) EcoRI and HindIII

Please explain how to get the answer!

EcoRI (5500) 7000 bp HindIII (1750) EcoRI (2000) Sacl (4000) Lane 1 Lane 2 Lane 3 Lane 4 7000 3500 3250 2000 1500 250

Solution

Answer is b) EcoRI

This enzyme uses to digest the intact, circular plasmid because EcoRI(7500) cleaves the DNA molecule at specific site, ensuring that all DNA fragments that contain a particular sequence of base have the same size.

Further the fragment that contains the desired sequence (7000) has the sequence located at exactly the same position within the fragment.

EcoRI (5500+2000 = 7500) is more than 7000 bp