Question

Explain how would you screen for the positive colonies after introducing your recombinant plasmid into bacteria on agar plate

Answer 1

To screen recombinant positive colonies we use two different methods.

1. Antibiotic selection method: In this method we introdcue the gene of interest in selection antibiotic marker. When the GOI integrated in that gene, that gene inactivates, it is called as insertional inactivation. So, the recombinant one can not grow on that particular antiobiotic media. So, we can pic recombinant colony from mother plate.

2. Non antibiotic selection method : The most famous method is blue white screening.

In this selection, the GOI will insert in to Gus gene, so it leads to inacitve prodcut of gus gene, it can not utilize GUS substarte so, instead of blue,colony apperas in white color.