Question

What happens when the vector dna is digested with EcoRI? What does this tell you about the number and distribution of EcoRI sites in the vector?

Answer 1

When a vector DNA is digested with restriction endonuclease such as EcoRI, the DNA molecule is cleaved at unique sites. EcoRI recognizes the six-base-pair sequence GAATTC in the vector DNA. Depending on the number of sites this sequence is present in the vector, the DNA molecule is cleaved at those site. For example if this sequence is present at five sites in a vector DNA, then endonuclease EcoRI will digest the DNA molecule into six fragments ranging from 3.6 to 21.2 kilobases long.

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