Where Am I ? >  Unit Introduction > Step 5
Step 5. Extraction, Purification and Quantitation of DNA from Lizard Skin

Before commencing work we need DNA of sufficient purity and amount. After extraction and purification steps the DNA needs to be quantitated to ensure quantity and to gain an indication of its purity.

Extraction usually uses some kind of solvent to disrupt cells and tissues to release the DNA followed by precipitation and purification of the DNA.

One method of quantitation is performed by measuring the DNA concentration in a spectrophotometer at two wavelengths - 260 nm (A260) and 280 nm (A280).

Photo of a spectrophotometer.

A260 gives the concentration of the DNA and the ratio of A260/A280 indicates the level of contamination by RNA or protein.

For more information on the use of the spectrophotometer to measure biological samples read the following Study Notes that are available in the Resources and Training Room:

manual icon MTH 47 SOP: Care and maintenance of the Spectrophotometer

manual icon MTH 67 SOP: Spectrophotometer - Bacterial Suspension and Browning Enzyme Analysis

Click on the following link to obtain a method for the extraction of DNA from lizard skin and use this SOP to do an activity on DNA extraction. Lizards that provided the skin used for DNA analysis.

manual icon MTH 109 SOP: DNA Extraction/Purification of DNA from Lizard Skin

activity icon Activity: DNA Extraction/Purification of DNA from Lizard Skin

Click on the following link to obtain a method for the quantitation of DNA with the spectrophotometer and use this SOP to do an activity on DNA quantitation.

manual icon MTH 110 SOP: DNA Quantitation

activity icon Activity: DNA Quantitation

 


   Where Am I ? >  Unit Introduction > Step 5