BBa K338002

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Fused heat shock promoter with lacI regulated promoter. It possesses the characteristics of both a heat shock promoter and LacI.

Usage and Biology

BioBrick Characterization

Effect of Heat Shock Temperature

A DH5α cell culture containing HSP-LacI-GFP was divided into four samples. At the beginning of the incubation period, IPTG was added to Samples 2 and 3. Then Samples 3 and 4 were heat shocked at 42°C for 2 hours. At the end of the incubation period, measurements of the fluorescence level of GFP were taken using the plate reader at 20 minute intervals and were averaged over a 1 hour interval. The vertical axis is raw fluorescence units normalized by OD₆₀₀. Normalized value of each sample at t=0 was subtracted from all the values to show a relative difference.

Experiment suggests that heat shock combined with IPTG creates the highest level of activation.

Effect of Glucose

DH5α cells containing HSP-LacI-GFP were grown in LB solution with 0 mM and 5 mM glucose with a controlled culture containing only HSP. Measurements of fluorescence level of GFP were taken using the plate reader.

In non-LacIq cells such as DH5α, LacI is not fully suppressed. Glucose was used to regulate the LacI promoter. As shown above, with the addition of 5 mM glucose, the production of GFP decreased 5 fold compared to cells grown in glucose-free solution.