Team:LCG-UNAM-Mexico/Wet Lab/Experiments

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Contents

C1a growth plot

C1a is a k12-derivative strain. In order to know the behavior of this strain we did a growth curve. Every four hours two samples were taken from a C1a culture. We measured the OD (550nm) of one of those samples, and the other was used to do dilutions and to plate them. The results are shown in the next table.

 tiempo (hrs)	DO 550nm	UFC/ml
 0		0.0355		1207000
 2		0.2533		25450000
 4		0.944		160000000
 6		1.2194		165000000

A non-linear regresion method was used to generate a logistic formula with the best adjustment.
UFCvstime.png
The unit time is hours, the y correspond to UFC and the x correspondst to time ODvstime.png
The unit time is hours, the y correspond to OD and the x correspondst to time

Both formulas were used to infer a correlation formula between OD and UFC, this formula was used to translate the OD measures to UFC. FormulaeODvsUFC.png


T3 and T7 infection plot

Without system

Growth T3 t7.png

With system

Burst size determination

Without system

With system

Test parts and devices


Multipromotor

We will test the functionality of both T3 and T7 promoters trhough the induction with IPTG of the strain BL21(DE3)pLysS in the case of T7. We are going to extract by PCR the RNA polymerase of the phage T3 and clone it under the control of a promoter inducible with IPTG.
In both cases we expect to see the presence of fluorescence under uv light.

Quorum sensing system

After assembling the quorum sensing device, we will turn on the system by any of the RNA polymerases. We expect to see green florescence in the point of induction and red in the neighborhood. At this point the toxines won't be in the construction to avoid the noise caused by the death.

asRNA

We will induce the asRNA construction with IPTG, afterwards we expect the infection of T7 and T3 to be with less efficiency of plaquing.

Toxins

The colicines (E3 and E9) will be under the transcriptional regulation of the promoter induced by IPTG. We will do a growth curve following the same procedure used to do the c1a growth curve as performed above . We will feedback the model with these results. We expect this curve to decay before the wild type curve. We will do another curve using the same procedure described in the section phage infection curve. We expect the growth curve obtained to decay before than that of the phages infection curve. We hope the toxic activyty of the toxins will be faster enough to kill the bacteria before the phages.