Question

Results 3. (5 points) Our transformation procedure used 10 u of 0.08 ug/ul PGLO. How does the concentration of DNA affect the number of colonies and the transformation efficiency? Do you think if we used more concentrated PGLO that we could have gotten a higher transformation efficiency? The numbers of colonies shown below resulted from transformation with 10ul of PGLO at the concentrations shown. a. Calculate the transformation efficiency at each concentration. Express your answers in scientific notation. Write the answers in the column on the left side of the table below. All TEs must be correct to earn the points. PGLO concentration (ug/ul) 0.00001 Colonies Counted Transformation Efficiency (col/ug) 2.0x10 col/ug 1.6x10' col/ug 0.0001 2.2x10 col/ug 0.001 2.5x10* col/ug 0.01 0.1 2.6x10' col/ug

Answer 1

3. Transformation is the process of internalisation of foreign DNA by the cells. The property of the cells which allow hem to take up foreign DNA is known as competency. Competency is the ability of the cells for taking the foreign DNA. Cells are made competent by various ways chemical, electrical etc.

The concentration of DNA does affects the transformation efficiency. It is affected by the competency of the cells. If the cells are more competent then the chances of taking the DNA and getting transformed will be more. But in reality all cells are not competent enough to do so. Therefore more amount of DNA is required to increase the chances of getting transformed. Higher the competency of the cells, lesser the amount of DNA used for transformation , higher will be the transformation efficiency. Transformation efficiency is reflected in terms of the number of transformed colonies that appear on the plate.

There is an inverse relationship between the DNA concentration and transformation efficiency because of the inhibition posed by the competition as the number of DNA molecules increases.

If we have used concentrated pGLO then the colony number on plate will be higher. It can be also seen in the table provided below where a higher concentrated pGLO is yielding more number of colonies i.e. 0.1 ug/ul yields 516 colonies but the transformation efficiency decreses. This is due to the inhibitory effect of DNA on the cells due to competition.

As seen in case 1 of table provided where 0.00001ug/ul of DNA( less concentrated) yielded higher transformation efficiency although the number of colonies are very less 4 only. This is beacuse of the fact that inhibitory effect is absent because of less DNA molecules present for internalisation.

If the cells are highly competent then the transformation efficiency will be more it suggests that chances of getting positive succesfully transformed colonies will be more, even if the total number of colonies are less.