Q. What creates DNA fragments with sticky ends?
If another piece of DNA has matching overhangs (for instance, because it has also been cut by EcoRI), the overhangs can stick together by complementary base pairing. For this reason, enzymes that leave single-stranded overhangs are said to produce sticky ends.
Q. Which enzymes produce sticky ends?
Longer overhangs are called cohesive ends or sticky ends. They are most often created by restriction endonucleases when they cut DNA. Very often they cut the two DNA strands four base pairs from each other, creating a four-base 5′ overhang in one molecule and a complementary 5′ overhang in the other.
Q. What cuts strands of DNA into fragments?
In the laboratory, restriction enzymes (or restriction endonucleases) are used to cut DNA into smaller fragments. The cuts are always made at specific nucleotide sequences. Different restriction enzymes recognise and cut different DNA sequences.
Q. What are the fragments in the DNA called?
A restriction fragment is a DNA fragment resulting from the cutting of a DNA strand by a restriction enzyme (restriction endonucleases), a process called restriction.
Q. What are DNA fragments used for?
Uses. DNA Fragmentation plays an important part in forensics, especially that of DNA profiling. Restriction Fragment Length Polymorphism (RFLP) is a technique for analyzing the variable lengths of DNA fragments that result from digesting a DNA sample with a restriction endonuclease.
Q. Where does ethidium bromide stain DNA?
The most commonly used stain for detecting DNA/RNA is ethidium bromide. Ethidium bromide is a DNA interchelator, inserting itself into the spaces between the base pairs of the double helix. Ethidium bromide possesses UV absorbance maxima at 300 and 360 nm.
Q. Why is SYBR green better than EtBr?
SYBR Safe. SYBR safe is a commercial DNA stain manufactured by Invitrogen. It is marketed as less harmful than ethidium bromide, but this is debatable. Its major advantage is that it is as sensitive as ethidium bromide but does not require UV light for visualization.
Q. How do you clean ethidium bromide?
Using paper towels dry up the area and then wipe the area down with absorbents dipped in tap water. Repeat this process until the area is clean. Using a UV light, check the area to ensure that all the ethidium bromide has been removed. Repeat decontamination procedure as necessary.
