Purpose
BBa_J23119 serves as the constitutive promoter to drive gene expression. The contribution experiment from Mingdao in 2025 characterizes the activity of the J23119 promoter.
Method
We had a reporter gene, which is the Green Fluorescent Protein (GFP), to show the promoter activity in the expression. Thus, the intensity of the fluorescence will provide clear evidence of how much gene expression the promoter has driven. The GFP glows green when it is expressed. The test includes the OD600 of the J23119-empty, with the promoter present but no GFP, and the J23119-GFP, which means the promoter is driving GFP. If the promoter itself exhibits baseline values, and the J23119-GFP performs a much higher ratio, it can be proven that J23119 is likely an active constitutive promoter. There are major reasons why we repeated the indicators (J23119-empty and J23119-GFP) twice and into groups are that it offers technical reliability to the data, and it demonstrates that the results can be reproduced, not random. That said, repeating it twice can help us in calculating the standard deviation and the mean as shown in the following figures.
Result
We had a reporter gene, which is the Green Fluorescent Protein (GFP), to show the promoter activity in the expression. Thus, the intensity of the fluorescence will provide clear evidence of how much gene expression the promoter has driven. The GFP glows green when it is expressed. The test includes the OD600 of the J23119-empty, with the promoter present but no GFP, and the J23119-GFP, which means the promoter is driving GFP. If the promoter itself exhibits baseline values, and the J23119-GFP performs a much higher ratio, it can be proven that J23119 is likely an active constitutive promoter. There are major reasons why we repeated the indicators (J23119-empty and J23119-GFP) twice and into groups are that it offers technical reliability to the data, and it demonstrates that the results can be reproduced, not random. That said, repeating it twice can help us in calculating the standard deviation and the mean as shown in the following figures.
Figure 1
In Figure 1, OD600 has a sustained growth. This demonstrates that the promoter's presence would not inhibit the growth of the cell. Next, the fluorescence is normalized, which means dividing the fluorescence by OD600 to account for the measure of GFP expression per cell.
Figure 2
As in Figure 2, the results show that both indicators of the J23119-GFP have higher ratios compared to the J23119-empty group. This explains the promoter’s activity that the reporter gene shows can drive the GFP expression. It starts from the third hour that continues to increase per cell. Until the maximum point in the ninth hour, it has a continuous growth over time. This can further demonstrate J23119's capability by telling how many cells there are because it can maintain the growth for a very long time. Thus, it confirms that J23119 is an active constitutive promoter.