PRE LAB EXPT 5 (DAY 2)

Calculation of percent yield

• weigh the dried isolated DNA from day 1

• calculate the percent yield using the formula

Hydrolysis

• Divide the DNA sample collected for part B and C of the experiment

• Place the isolated DNA dedicated for part B into a test tube and add 20 drops of 6M sulfuric acid

• Label the test tube “B1” and cover with aluminum foil

• Heat the test tubes in a boiling water bath for one (1) hour with occasional shaking

• Cool the misture at room temperature and add 2ml of distiilled water. This will serve as your blank

• Record Observations of the characteristic of the DNA sample (test tube B1) and the blank (test tube B2) at the “Hydrolysis” row of your data sheet

• To both test tubes, add 2ml of dische reagent

• Heat the tubes for 10 minutes in boiling water bath

• Cool the solutions and note your observations at the “dische reaction" row of your data sheet

Dische reaction (without hydrolysis)

• Prepare 3 clean and dry test tubes and label them test tube C1, test tube C2, and test tube C3

• Suspend the previously set aside DNA set in 3ml distiled water and mix using a vortex mixer. This will serve as your DNA solution

• For every test tube, add the following samples:

  • C1 - 2ml DNA solution

  • C2 - 1ml DNA solution + 1ml distilled water

  • C3 - 2ml distilled water (blank)

• Add 2ml of dische reagent to each test tube and mix thoroughly

• Place all test tubes in a boiling water for 10 minutes. Cool th solutions and note your observation

• Evaluate your results by using the statements below as reference

  • clear tube - no nucleic acids

  • blue color - presence of DNA

  • greenish color - presence of RNA

Clear tube

indicates no nucleic acids

Blue color

indicates the presence of DNA

Greenish color

indicates the presence of RNA

All waste

disposal container: organic waste bottle