Question

This is what we did in the experiment .First of all,1 µl of plasmid DNA was added into the tube which contains competent cells and the tube was tapped gently to mix DNA and the competent bacteria. After that it was placed on ice for 30 minutes. Then, the tube with the competent bacteria and plasmid were transferred to heating block at 42 °C and the tube was leaved in there exactly 90 seconds. 0.25 ml of LB broth was added to the tube and incubated 20 minutes at 37°C . After that, with using aseptic techniques pipette, the entire contents of the 500 µl X-gal/IPTG vial was put onto the agar plate which is labelled and with using glass spreader, it was dispersed. 200µl of bacteria which has the plasmid was spreaded onto the agar plate with glass beads. Then, the plate was inverted and incubated 37°C overnight and one week later the results were observed and there were some blue colonies on the agar plate.

explain the results for your own group and compare to other groups -especially if a group has a different result than yours , discuss possible errors?? how do you come to this conclusion ? did you observe the alpha complementation or not?

what do the control plates prove to you?did you see only blue colonies or were there any white ones as well and why?

and how to heal our results? no copy-paste, please.

this is our result and there are some blue colonies at the bottom and no white ones.

- Gre Groups 2.6 PMS #Anpeln 06/05/20 48 + lol

Answer 1

• In your result of your group the colonies are blue so that active beta galactosidase is present and due to the activity of the Xgal the cololonies looks blue that means no insert is present. it means no transformation has been occured.
• In the white colonies the active formation of the betagalactosidase is intterupted so that no color is produced due to the activity of the Xgal.
• The error comes when the lacz becomes defective due to certain reasons and then it would not produce any color and despite the product will not be recombinant it will show white colony means recombinant.
• So the conclusion in our case will be no recombinant has been produced.
• Alpha complementation is seen when the alpha peptide causes the inactive mutant form of bgal to active form so in case of blue colonies the alpha complementation happens.
• Control should have the blue colonies IF white ones found the colonies have been transformed.
• The transformation has not been happened due to some reasons in your result. no recombinant found.