An Investigation Into the Induction and Inhibition of ß-Galactosidase Expression by E. Coli, Using a Bacterial Expression Vector

APPENDIX A

Original Data

Table 1: Absorbance values obtained for standard solutions of o-nitrophenol, used to construct a standard curve

|[o-nitrophenol |10 |20 |40 |60 |80 |100 |

|(µM) | | | | | | |

|Replicate 1 |0.173 |0.348 |0.668 |1.022 |1.056 |1.778 |

|Replicate 2 |0.173 |0.356 |0.67 |1.007 |1.065 |1.77 |

|Average |0.173 |0.352 |0.669 |1.015 |1.061 |1.774 |

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Graph1: Standard curve for o-nitrophenol with concentration range of 10 – 100 µM

Table 2: Results of ß-galactosidase assay of E. coli cells’ content, after treatment with different inducers

|Inducer used |Water |Lactose |IPTG |Melibiose |Galactose |

|Absorbance410nm Replicate |0.186 |0.229 |3.579 |0.188 |0.358 |

|1 | | | | | |

|Absorbance410nm |0.216 |0.225 |3.579 |0.269 |0.426 |

|Replicate 2 | | | | | |

|Average Absorbance410nm |0.201 |0.227 |3.579 |0.229 |0.392 |

Table 3: Concentrations of o-nitrophenol present in cells’ content after treatment with different inducers, as determined by ß-galactosidase assay...