Team:Tec-Monterrey/antifreeze/results

Conclusions RiAFP



RiAFP presence was not conclusively determined by SDS-PAGE; nevertheless, RiAFP viability tests demonstrated significant difference between positive and negative transformants, suggesting expression of the protein in the cells. Further experimentation with variable inductor concentrations would be needed to optimize cryopreservation conditions of RiAFP, as well as longer storage periods. Given the advantages of the RiAFP transformants, we speculate, increase in the competency of RiAFP (+) cells will be measured by comparing the transformation efficiency between positive and negative RiAFP-transformants.

Experiment 1

The standardization of the protocol for testing the viability of cells producing antifreeze proteins was based on the article "Evaluation of tolerance for cryopreservation of two strains of Escherichia coli K12 often used in biotechnology" and iGEM Amsterdam 2011’s protocol.

1) Three strains were tested TOP10, JM109, and BL21. Using strains transformed with AFP and untransformed (as control) 2) The strains were placed at -20 ° C for 24 hours Tec-Monterrey iGEM 2012 3) Thaw for 2 hours on ice 4) Inoculated in plates in a dilution of 10 ^ -5 (cycle 0) 5) The cells were frozen for 2.5 hours (-20 °C) 6) Afterwards they were placed 20 min on ice and inoculated in a dilution of 10 ^ -5 (cycle 1) 7) The cells were frozen for 1 hour 8) Thaw for 20 minutes on ice and inoculated in a dilution of 10 ^ -5 (cycle 2) 9) Freeze for 1 hour 10) Thaw for 20 minutes on ice and inoculated in a dilution of 10 ^ -5 (cycle 3) 11) Freeze for 1 hour 12) Thaw for 20 minutes on ice inoculated in a dilution of 10 ^ -5 (Cycle 4) 13) Incubate at 37 ° C

Results

The plates resulted countless so the protocol needed to be restructured



Experiment 2

The protocol was re-standardized to prove the viability of the cells producing anti-freeze proteins. 1) Two strains were tested TOP10 and JM109. Using strains transformed with AFP and untransformed (as control)

2) The strains were placed at -20 ° C for 24 hours 3) Thaw for 1 hour on ice 4) Inoculated in plates in a dilution of 10 ^ -5 (cycle 0) 5) The cells were frozen for 1 hour (-20 °C) 6) Afterwards they were placed 1 hour on ice and inoculated in a dilution of 10 ^ -7 (cycle 1) 7) The cells were frozen for 1 hour 8) Thaw for 1 hour on ice and inoculated in a dilution of 10 ^ -7 (cycle 2) 9) Freeze for 2 hour 10) Thaw for 1 hour on ice and inoculated in a dilution of 10 ^ -5 (cycle 3) 11) Freeze for 1 hour 12) Thaw for 30 minutes on ice inoculated in a dilution of 10 ^ -7 (Cycle 4) 13) Freeze for 1 hour 14) Thaw for 30 minutes on ice inoculated in a dilution of 10 ^ -7 (Cycle 5) 13) Incubate at 37 ° C

Results

The plates inoculated with transformed cells did not show growth while the non-transformed did show growth.

Experiment 3

The protocol was re-standardized one last time to prove the viability of the cells producing anti-freeze proteins.

1) Two strains were tested TOP10 and JM109. Using strains transformed with AFP and untransformed (as control), and also induced cells with arabinose+salt and arabinose by itself and non-induced cells to prove the effect of the inductor. 2) Cells were induced to 32°C for 12 hours; with arabinose+salt, arabinose, and non-induced cells. 3) The strains were placed at -20 ° C for 24 hours 4) Thaw for 3 hour on ice 5) Inoculated in plates in a dilution of 10 ^ -5 (cycle 0) 6) The cells were frozen for 4 hours (-20 °C) 7) Afterwards they were placed 3 hours on ice and inoculated in a dilution of 10 ^ -5 (cycle 1) 8) The cells were frozen for 2 hours 9) Thaw for 1 hour on ice and inoculated in a dilution of 10 ^ -3 (cycle 2) 10) Freeze for 1 hour 11) Thaw for 30 min on ice and inoculated in a dilution of 10 ^ -3 (cycle 3) 12) Incubate at 37 ° C

Results

Results were observed in all plates (See Results)