We are using pET-32 Xa/LIC kit (Novagen 70072-3) for cloning. In kit manual there is no media mentioned for plating the transformants. We have used the LB culture medium. But there is no colony found of positive control insert on LB plates. Should we use SOC media for plating?
Is there any difference between LB or SOC media to select transformants?
Hello
Yes, there is a difference. Compared to LB, SOC is rich in nutrients. It will be helpful.
Please refer to the research article given below.
https://doi.org/10.1016/j.ab.2009.07.023
Good Luck.
As mentioned by Malcomji, SOC is quite rich in nutrients compared to LB but to be honest I never found any much difference in getting positive colonies when using SOC over LB. Since pET-32 Xa is plasmid for expressing high amount of proteins, I hope you are using good quality BL21 or other E coli cells with the appropriate antibiotics for selection. Also make sure the plates which you have prepared are fresh and have the recommended conc of antibiotics.
From a practical standpoint, either LB or SOC works just fine as a recovery media for E. coli. The issue is more likely to be in the quality of the competent cells or your skills in transformation. If it's a chemi-competent (temperature-shock) transformation, then having accurate temperatures & times is essential. When the kit says 42* for 30 seconds, 2 min on ice - you have to do EXACTLY that protocol. Competent cells are very fragile, treat them like a vial of tiny, thin balloons.
Good luck!