DNA Isolation Report

Summary Table

Final Volume of DNA Preparation (mL) 2A260 0.521A280 0.252A260~A280 2.0675Purity Purity >2 possible RNA contaminationDilution factor used for UV spectrum 1:20Diluted [DNA] (μg/mL) 9.18Original [DNA] (mg/mL) 0.184Yield (mg)* 0.367

Yield (mg/g wet wt cells) 0.1835Expected Yield (mg) based on the theoretical calculations

0.734

The DNA Spectrum

MethodA culture of E.coli (~0.1g wet weight per mL), suspended in 0.1 M NaCl, 10 mM EDTA, pH 8. Incubated with a 2% w/v SDS for 10 minutes at 65 degrees. Following the incubation, Sodium Perchlorate was added to 1mM and the solution was extracted with an equal volume of chloroform: amyl alcohol (24:1) solution. After shaking for 20 minutes in a mechanical shaker at room temperature, remove the upper aqueous layer. Layer 2 volumes of 100% cold ethanol carefully on top of the solution. Collect the nucleic acid by spooling. The precippitate (nucleic acids) is then washed briefly in 70% (v/v) ethanol and then is dissolved in 10mM Tris and 1 mM EDTA (0.4 ml/mL of E.coli suspension). The quality and yield was assessed by the UV spectrophotometry and by gel electrophoresis and without RNAse treatment.

ExplanationThese changes would not alter the method because it uses the same concentrations to isolate and extract the DNA. However the values for SDS and the amount of DNA in the starting solution would change due to different however by altering the volumes used gives back a constant concentration to isolate the DNA.