SEPTEMBER, 27TH
PLATE
EXPERIMENT DESCRIPTION
Motivation
This experiment was performed to check bacterial growth and GFP rate synthesis of the following constructs in order to verify right protein folding.
Methods
Inoculum (into 5 ml LB+Amp) from glycerol stock of:
- I47
- I48
- I49
- <partinfo>BBa_K173000</partinfo> (positive control)
- <partinfo>BBa_B0031</partinfo> (negative control)
They were let grow ON at +37°C, 220 rpm.
The following day cultures were diluted 1:100 and let grow again for about five hours at +37°C, 220 rpm.
Optical density (O.D.) of each cell culture was than measured with TECAN Infinte F200. Samples were diluted in order to obtain the same O.D. equal to 0,02.
Than we performed a 21 hours' experiment with measurements of absorbance and green fluorescence every five minutes with TECAN Infinite F200. Each value shown is the mean of three measurements, from GFP data that of a non-fluorescent culture (negative control) was subtracted; cultures were shaken for 15 seconds every five minutes.
RESULTS
Culture | Doubling time [min.] |
<partinfo>BBa_K173000</partinfo> | 77 |
I47 | 74 |
I48 | 75 |
I49 | 76 |
<partinfo>BBa_B0031</partinfo> | 69 |
Mean of (dGFP/dt)/O.D.600
All cell cultures showed a similar growth curve and doubling time was computed as described here in order to have informations about the burden due to synthesis of such fusion proteins. It's possible to see
In GFP curve it's possible to appreciate that in I47, I48, I49 GFP accumulation it's very similar and it's significantly different from that of negative control <partinfo>BBa_B0031</partinfo>.
After an initial interval in witch GFP production rate was significantly higher in positive control <partinfo>BBa_K173000</partinfo> than in the other samples, GFP synthesis rate of I47, I48, I49 became very similar to this one. It was still lower than positive control, but was constant during all the experiment. This showed the right folding of the green fluorescent protein assembled downstream of the genetic circuit.
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