Synthetic biology and all the engineering disciplines need to be reliable and repeatable, this year iGEM TecCEM 2018 is one of the teams that participated in the Fifth International InterLaboratory Measurement Study. In this page, we report the results obtained during all protocols.
Competent cell - transformation DH5-alpha
Transformations of all devices were performed, and the resulting transformant strains were plated on LB agar, with 35 μg/mL chloramphenicol. Two colonies per plate were separated into two independent cultures.
Verification
We verified the presence and size of the device plasmids in the transformant strains by running an agarose gel electrophoresis.
Device | Part Number | Size (bp) |
---|---|---|
Negative Control | BBa_R0040 | 2124 |
Positive Control | BBa_I20270 | 2989 |
Device 1 | BBa_J364000 | 2988 |
Device 2 | BBa_J364001 | 2988 |
Device 3 | BBa_J364002 | 2988 |
Device 4 | BBa_J364007 | 2988 |
Device 5 | BBa_J364008 | 2988 |
Device 6 | BBa_J364009 | 2988 |
Calibration Protocol
The main objective of this calibration LUDOX protocol is to use LUDOX CL-X to get the conversion factor between absorbance (Abs600) from the plate reader and the OD600 measurement.
LUDOX CL-X | H2O | |
---|---|---|
Replicate 1 | 0.059 | 0.033 |
Replicate 2 | 0.061 | 0.033 |
Replicate 3 | 0.062 | 0.033 |
Replicate 4 | 0.060 | 0.033 |
Arith. Mean | 0.061 | 0.033 |
Corrected Abs600 | 0.028 | |
Reference OD600 | 0.063 | |
OD600/Abs600 | 2.291 |
Particle standard curve - Microsphere Protocol
The aim of this protocol is to establish a standard curve from a microsphere solution. These microspheres have similar size and optic properties to bacterial cells, therefore, they may be used to calibrate. After preparing the Microsphere Stock Solution, serial dilutions were made in a 96-well plate as instructed. To achieve reliable results, the plate reader was set to shake the samples just before reading them. The reads were registered in the given Excel file and are shown below.
Fluorescence standard curve - Fluorescein Protocol
Following the protocol for the fluorescence standard curve using fluorescein, we prepared the corresponding reactants and the requested serial solutions in the 96-well plate.
Cell measurement Protocol
Hour 0 | Hour 0 | Hour 6 | Hour 6 | |
---|---|---|---|---|
Abs600 Raw Readings | Fluorescence Raw Readings | Abs600 Raw Readings | Fluorescence Raw Readings | |
Negative Control | 0.078375 | 153.5 | 0.46225 | 170.125 |
Positive Control | 0.074 | 220.125 | 0.428125 | 1926.75 |
Device 1 | 0.0715 | 439.125 | 0.241 | 4319.5 |
Device 2 | 0.079125 | 266.625 | 0.442375 | 2148.5 |
Device 3 | 0.075625 | 151.125 | 0.430375 | 207.625 |
Device 4 | 0.074375 | 601.5 | 0.347625 | 5545.875 |
Device 5 | 0.075625 | 335.875 | 0.16425 | 2039 |
Device 6 | 0.077 | 227.125 | 0.45325 | 1151 |
LB + Chlor (Blank) | 0.053375 | 158.625 | 0.051125 | 177.5 |
After performing all three calibration measurements, we proceeded to execute the cell measurement protocol, previously having the overnight cell culture of each device and control. We use the same plate and volume that we used in the calibration protocol, also the same settings in order to make valid the measurement. We defined the difference between the measurement of the absorbance and fluorescence, starting in the hour 0 until the hour 6.