Post-lab Analysis

No post-lab assignment is due next week. However, you should get started on prompts 1–11 on the Assignment 5 Worksheet found on the D2L Main Page. The following information will help you to analyze your results.

Prompts 1–9

  • The DNA Isolation background and the pre-lab lecture contain information that will help you to explain the roles of the different chemical ingredients in the DNA isolation procedure.
  • Gel images for your lab section are found in the Images link in the Student Data area of the Main Page.
  • A complete caption for an agarose gel must state the percent agarose, identity of the running buffer, staining methodology, approximate sample mass of DNA loaded per lane, identity of lanes (i.e. DNA ladder or plasmid samples), and identity of important bands in reference ladder.

Prompts 10–11

  • To calculate the concentration of DNA, multiply the measured Absorbance at 260 nm by 50 ng/μL.
  • To estimate the total plasmid yield, multiply your measured plasmid concentration (in ng/μL) by the eluted volume (in μL).
  • To evaluate success, you need to know that the expected yield of plasmid extraction as described in Bimboim 1979 is about 1 μg of low copy number plasmid DNA from the 1 mL of culture (the amount of culture we used).3   Our plasmid is known to be a low copy number plasmid (10-50 copies per cell).  According to the manual for our kit, the spin column capacity is 20 μg of plasmid DNA.6  This is the upper limit of how much plasmid DNA we can isolate.