Quiz 12 Plasmids and Cloning

Which part of a plasmid let you "see" if the plasmid got into the bacteria during transformation?

 

Selectable marker (i.e. AmpR)

If you wanted to find the transcriptional regulatory elements for a gene that you have identified, what type of donor DNA would you use for a library.

Genomic

If you wanted to change the maximum insert size in your plasmid, which part of the plasmid would you change?

 

Origin of Replication

If you had another screenable marker, could you use LacZ as a selectable marker?

Yes BUT Just remember that you'd have to make sure that the bacteria you are transforming into is LacZ- and that you make sure the media only has lactose for a sugar source.

If you had another selectable marker would you want to use AmpR as a screenable marker?

No

technically you could use it but you would not want to as you'd have to do replica plating, the benefit of LacZ is that you can see both allelic states on a single plate.

Imagine you have a promoter X for a gene X and you are trying to find the transcription factor that binds it using a cDNA library that can express the cDNA insert in bacteria. How would you most efficiently create a screen to find this transcription factor.

 

Make another plasmid where promoter X controls a screenable marker to look for expression from promoter X.