In Team ITB_Indonesia 2017
characterization, we found in normal growth/incubation condition (37 oC, LB agar) that
-transformed Escherichia coli BL21 colony appear to need longer incubation time (>18
hours) until it clearly shows red color under natural light.
We then investigate whether this phenomenon is influenced by the strain, and we try if there are
lac repressor in the system that can be released by inducing the culture with IPTG, hence
increasing the expression of mRFP.
We used three different strains of transformed E. coli (BL21, DH5alpha, and Top10) for this
study. They were incubated in LB broth, 37 oC, and sampled every 4 hours for 2 days to
determine the red color absorbance at 588 nm. The amount of IPTG added for respective treatment is 500
Result and Findings
There are no significant differences of mRFP expression in different strains of E. coli
(BL21, DH5alpha, Top10)
There are no significant effects of mRFP increased expression after IPTG induction.
The red color absorbance under 588 nm wavelength is recorded around 2.5-3 OD units.
The broth become red in color under natural light around 16-20 hours of incubation time.