Where Am I ? >  Unit Introduction > Step 3
Step 3. Planning for Extraction of DNA

The essence of good laboratory practice is to be able to plan, prioritise work and allocate tasks. In this case using suitable DNA extraction, purification and amplification techniques. Selection of the most appropriate technique can be difficult in biotechnology due to the large number of published techniques (called applications by suppliers of biotechnology reagents and equipment).

In a nutshell, what you are trying to achieve is to have enough DNA of suitable purity to perform the testing on. Extraction and purification of DNA from animal tissues (in this case lizard skin) is usually performed in the one sequence of steps and is relatively straightforward but is not without its pitfalls for the inexperienced.

Often the amount of DNA extracted from a sample is insufficient for the testing required. In this case a technique called PCR (polymerase chain reaction) is used to amplify the DNA up to a million fold. PCR uses primers that attach to specific parts of the DNA sample and replicates the sequence between two primers. As well as increasing the amount of DNA available to work with it also allows only a required specific portion of the DNA to be amplified Image of a PCR machine.
Staff in the DNA laboratory pippetting the sample. In this step you will participate in a Forum regarding extraction/purification and amplification of DNA. Before you start the Discussion Forum you need to access some information on this topic.

Go to the Roche website and obtain information on the extraction of DNA from tissues. Go to the World Wide Web Catalogue and choose Web Visit - Roche from the list given.

www icon World Wide Web Catalogue

Now look at other sites using a search engine term such as ‘DNA extraction’ and obtain further information, especially alternative methods, of DNA extraction. The best sites to look at are company-based (suppliers to the biotechnology industry such as Roche above) or research based (e.g. university or biotechnology company research information). Look for at least one method of PCR amplification.

To search the Internet, go to the Resources and Training Room and use a search engine provided or use one of your own choice.

go to icon Resources and Training Room

When you have completed your Internet search go to the Forum and contribute to the discussion topic Extraction/purification and amplification of DNA.

Now undertake the following assignment about DNA extraction.

assignment icon Assignment: DNA Extraction, Purification and Amplification

Staff working in the DNA laboratory preparing the sample.

   Where Am I ? >  Unit Introduction > Step 3