3. Operations on DNA :

3. Operations on DNA :

While a number of equivalent formalizations exist, we follow the descriptions. Note that the types of operations available are result of the capability of molecular biology rather than the wishes of algorithms designers. Also note that this algorithms are performed in constant time on testtubes which, for the sake of this discussion, may be of arbitrary size this operations are :


1) MERGE :
This is the simple operations of combining the contents of two test tubes in a third tube.


2) ANNEAL :

This is the process by which complementary strands of DNA are paired to form the famous double-helix structure of Watson and crick. Annealing is achieved by cooling a DNA solution, which encourages pairing. Adleman uses this in step 1 to generate all legal paths through the graph.



3) MELT :

Melting is inverse operation of annealing. By heating the contents of a tube, double-stranded DNA sequences are denatured, or separated into its two single-stranded parts.

4) SEPERATION BY LENGTH :

The contents of test tube can be separated by increasing length. This is achieved by hel electrophoresis, whereby longer strands travel more slowly through the gel. This operation was used by Adleman in step 3 of his solution to HP.


5) SEPERATION BY SEQUENCE :

This operation allows one to remove from solution all the DNA strands that contain a desired sequence. This is performed by generating the strands whose complement is the desired sequence. This newly generated strands is attached to magnetic substance which is used to extract the sequences after annealing. This operation crux of Adleman’s step 4 .


6) COPYING/AMPLIFICATION :

Copies are made of DNA strands in a test tube. The strands to be copied must have known sequences at both the beginning and end in order for this operation to be performed.


7) APPEND :

This process makes a DNA strand longer by adding a character or strand to the end of each sequence.


8) DETECT :

It is also possible to analyze test tube inorder to determine whether or not it contains atleast one strand of DNA.



This operation, for example, is the last in Adleman’s algorithm where we attempt to find a DNA sequence that has survived the previous steps.