Bacterial Transformation

By Lexi Chase & Colleen Magowan

Stanley Cohen and Herbert Boyer ● Studied E. Coli PSC101 gene

● Transfers antibiotic resistance● Also transferred frog genes to

bacteria

Restriction Enzymes

● Cuts plasmid at one specific sequence

● Creates sticky ends

LigaseGlue plasmid & old DNA

together: creates recombinant DNA

Antibiotic resistant plasmid was being created

Heat Shocking the E. Coli…● Creates a pressure

difference between inside and outside of the cell

● Forms pores--->new genes (from plasmid) get in

How did they find it?● DNA sequencing WITHOUT COMPUTERS● Lots of guess and check● By hand, they searched for repetition and

patterns within the human genome (1,000’s of genes)

Results

● Bacteria that grew in the presence of both antibiotics contained the recombinant DNA

● Bacteria that only grew on one contained the old plasmids

Yes!Cohen & Boyer went on to add toad genes

to bacteriaLater generations of bacteria kept making

the toad proteins from the genesInterspecies gene swaps are possible

Can we do this with human genes?

Heat shocking: is it worth it?

Yes!

● Less efficient without heat shocking

Sourceshttp://www.genomenewsnetwork.org/resources/timeline/1973_Boyer.php

http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/pharmaceuticals/preserving-health-with-biotechnology/berg-boyer-cohen.aspx

https://www.google.com/search?q=fire&rlz=1C1CHWA_enUS626US626&source=lnms&tbm=isch&sa=X&ved=0ahUKEwisnq3x59XKAhXGph4KHfZQC2AQ_AUIBygB&biw=1366&bih=599#tbm=isch&q=fire+clipart&imgrc=I74Li8iHvTBcgM%3A

https://en.wikipedia.org/wiki/African_clawed_frog

http://parts.igem.org/Part:BBa_K338001

http://www.bville.org/teacherpage.cfm?teacher=427