There are two methods used for cutting DNA into small pieces – this is via ultrasound and restriction enzymes. Which method is considered better and why?
Since this is not my area of expertise, I searched Google under the key words "'Cutting DNA' ultrasound 'restriction enzymes'" to get these possible sources:
http://books.google.com/books?id=MPkwi-i33zYC&pg=PA134&lpg=PA134&dq=%22Cutting+DNA%22+ultrasound+%22restriction+enzymes%22&source=web&ots=19vwyKa7qL&sig=OL0nFbjDv10Yzj2lp3laRn2Kd5U&hl=en
http://www.answers.com/topic/genetic-engineering?cat=technology
http://bookweb.kinokuniya.co.jp/guest/cgi-bin/bookseaohb.cgi?ISBN=1405135441&AREA=05&LANG=E
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps. Thanks for asking.
To determine which method, ultrasound or restriction enzymes, is considered better for cutting DNA into small pieces, we need to compare the advantages and limitations of each method.
Ultrasound is a physical method that uses high-frequency sound waves to break DNA into smaller fragments. It is a relatively quick and straightforward technique, as it does not require any specific sequence recognition. Here's a general procedure for using ultrasound to shear DNA:
1. Start by preparing a DNA sample in a suitable buffer solution.
2. Place the sample in a container and expose it to ultrasound waves generated by an ultrasound machine.
3. The high-frequency waves create mechanical shearing forces that break the DNA strands into smaller fragments.
4. After the treatment, the DNA fragments can be further purified and analyzed.
Advantages of using ultrasound for DNA fragmentation:
1. It does not require any specific sequence recognition, so it can be used for DNA from any source.
2. It is a relatively quick and efficient method.
3. It does not introduce any foreign material or enzymes into the DNA sample.
However, there are some limitations to using ultrasound for DNA fragmentation:
1. It produces random breaks, resulting in a mixture of DNA fragment sizes.
2. It may cause DNA damage and sequence biases due to the shearing forces.
3. It is less precise than other methods, making it less suitable for certain downstream applications, such as cloning or sequencing.
On the other hand, restriction enzymes are highly specific protein molecules that recognize and cleave DNA at specific recognition sequences. Here's a general procedure for using restriction enzymes to cut DNA:
1. Start by preparing a DNA sample in a suitable buffer solution.
2. Add the appropriate restriction enzyme(s) to the sample and incubate it at an optimal temperature for the enzyme(s) to act.
3. The restriction enzyme(s) specifically bind to their recognition sites in the DNA and cleave the DNA at or near these sites.
4. After the digestion, the DNA fragments can be further purified and analyzed.
Advantages of using restriction enzymes for DNA fragmentation:
1. It allows for precise and specific cutting of DNA at specific recognition sites.
2. It produces DNA fragments with defined sizes and ends, making them suitable for various downstream applications, including cloning and sequencing.
3. It is compatible with many commercially available restriction enzymes that recognize different DNA sequences.
However, there are some limitations to using restriction enzymes for DNA fragmentation:
1. It requires prior knowledge of the DNA sequence and the presence of appropriate recognition sites for the chosen restriction enzyme(s).
2. It may have limitations in the availability of restriction enzymes that recognize specific sequences.
3. It may have difficulties in cutting DNA with heavily modified or unusual sequences.
In summary, the choice between ultrasound and restriction enzymes depends on the specific requirements of the experiment or application. Ultrasound can quickly and easily break DNA into smaller fragments but may be less suitable for precise applications. Restriction enzymes, on the other hand, offer precise and specific cutting of DNA at specific recognition sites, making them more suitable for downstream applications requiring defined fragment sizes and ends.