After A Shuttle Vector Essay

847 Words2 Pages

A shuttle vector is designed to be able to propagate in two different species, for instance E. Coli and yeast. This, in turn, allows for the manipulation of DNA in a host species which might be easier to handle than the target host.
1.16 NO CLEAVAGE PRODUCTS ARE OBSERVED AFTER A DNA RESTRICTION ANALYSIS. HOW WOULD YOU TROUBLESHOOT THIS PROBLEM?
The decision tree presented in Figure 2 could be followed.
1.17 WHAT KIND OF POSITIVE/NEGATIVE CONTROLS ARE USEFUL WHEN YOU TRANSFORM A LIGATION MIX IN E. COLI?
Several strategies might be used:
1) Uncut vector alone: shows if the transformation works. If positive, many colonies would appear.
2) Cut vector alone without ligation would result in no colonies. If they appear, it means that the vector was not …show more content…

To cut DNA, all restriction enzymes make two incisions, once through each strand of the DNA double helix.
1.23 WHAT ARE RESTRICTION ENZYMES?
As suggested by the previous question, a restriction enzyme (or restriction endonuclease) is an enzyme that cuts DNA. This is usually done at or near specific recognition nucleotide sequences (restriction sites).
1.24 WHAT TYPES OF RESTRICTION ENZYMES DO YOU KNOW?
Traditionally there are 4 classifications of restriction enzymes:
i. Type I: they are complex, multisubunit enzymes with a combination restriction-and-modification activities that cut DNA at random places far from their recognition sites. They need ATP to function. ii. Type II: Unlike type I restriction enzymes, type II enzymes cut DNA at specific recognition sites (with usually 4-8 nucleotides in length) and close to them. They do not need ATP or AdoMet for their activity, but might require only Mg2+ as a cofactor. iii. Type III restriction enzymes share with type I the need ATP to function, and they are also large and multisubunit proteins. They cleave DNA about 20-30 base pairs after the recognition site. iv. Type IV enzymes only cleave modified -typically methylated- DNA.
1.25 WHAT IS

Open Document