Which bacterial plates control for:
1) If the E. coli cells were transferred correctly:
2) If the E. coli cells can grow on LB:
3) If the Ampicillin is working correctly:
4) If the “stock” E. coli cells were contaminated with plasmid:
Possible choices for each number are:
"-"LB
"+"LB
"-"LB/Amp
"+"LB/Amp
"+"LB/Amp/Sugar
(LB is a growth medium)
("+" means the plate contains pGLO gene, which gives the bacteria resistance to Amp; "-" means it does not have pGLO)
(Amp is ampicillin)
(sugar gives fluorescent glow in presence of pGLO)
Please help me out. Thank you!
To control for each condition, you should compare the growth of E. coli cells on different plates. Here's how to interpret the results for each condition:
1) If the E. coli cells were transferred correctly:
- Take two plates: one with "+" LB (pGLO) and one with "-" LB (no pGLO).
- Inoculate both plates with the E. coli cells that were transferred.
- If the cells were transferred correctly, you will observe growth on both the "+" LB and "-" LB plates.
2) If the E. coli cells can grow on LB:
- Take two plates: one with "+" LB (pGLO) and one with "-" LB (no pGLO).
- Inoculate both plates with the same E. coli cells.
- If the E. coli cells can grow on LB, you will observe growth on both the "+" LB and "-" LB plates.
3) If the Ampicillin is working correctly:
- Take two plates: one with "-" LB (no pGLO) and one with "+" LB/Amp (pGLO + Amp).
- Inoculate both plates with the same E. coli cells.
- If Ampicillin is working correctly, you will observe growth only on the "+" LB/Amp (pGLO + Amp) plate and no growth on the "-" LB (no pGLO) plate.
4) If the “stock” E. coli cells were contaminated with plasmid:
- Take two plates: one with "+" LB (pGLO) and one with "+" LB/Amp/Sugar (pGLO + Amp + Sugar).
- Inoculate both plates with the same E. coli cells.
- If the "stock" E. coli cells were contaminated with the plasmid, you will observe growth on both the "+" LB (pGLO) and "+" LB/Amp/Sugar (pGLO + Amp + Sugar) plates. The presence of growth on the LB/Amp/Sugar plate indicates contamination.
By comparing the growth patterns on these different plates, you can control for each of the four conditions mentioned.