1. On which plate do you expect bacteria to glow when viewed under UV light? Whi

Question

1. On which plate do you expect bacteria to glow when viewed under UV light? Which will grow more colonies than others? Fill in applicable options: all glow / some glow, some don’t / none glow / more colonies / less colonies

Both gfp transformed and untransformed bacteria in normal light: (LB no Ampicillin plate)?
Both gfp transformed and untransformed bacteria in normal light: (LB with Ampicillin plate)?
Both gfp transformed and untransformed bacteria in UV light: (LB no Ampicillin plate)?
Both gfp transformed and untransformed bacteria in UV light: (LB with Ampicillin plate)?

2. Why do you think you only plate a small amount of the bacterial solution on the LB-Amp plate? (and even lower aliquots onto the LB plate?)

3. If you start with 1000 bacteria in your tube of competent cells and you know 1) that these bacteria double every 20 minutes and 2) 50% of them get transformed, how many bacterial colonies would you expect to see if you plated the entire solution on one LB+AMP plate and incubated them for 1 hour? How many colonies would be you expect on an agar plate if you plated 1/2 the total volume of the culture?

4. When you incubate the cells in 42C water and then immerse them in ice, what is this process called and how does this cause transformation? Why is this a shock to bacteria? What temperature is that in Fahrenheit?

Explanation / Answer

Question 1 answered

GFP, the Green fluorescence protein glows when exposed to blue to ultraviolet range. Although only those colonies will glow which are transformed. Growth will be more in no-ampicillin supplied plate as only transformed cells which also carry the ampicillin gene (generally used as a selectable marker).

Question 2 answered

A small amount of solution dilutes the bacterial population enough for the individual cells to be separated and spread so that the individual cells give rise to pure colonies upon incubation.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.