Sequence alignment using Longest Common Subsequence algorithm The way of detecting the similarity of two or more sequences is to find their longest common subsequence. Longest common subsequence (LCS) of two sequences is a subsequence, of maximum possible length, which is common to both the sequences. Let's consider an example. Suppose we have the following two DNA sequences: TAGTCACG and AGACTGTC. The LCS of the two sequences is AGACG, which can be obtained from the following alignment. TAGTCAC-G-- || || | -AG—ACTGTC There are other possible common sequences of shorter length, such as AGCG or AGTC. Although multiple LCS are possible in general, there is only one LCS for this particular example, that is, there is no other common subsequence of length 5 for these two sequences. The LCS also helps in computing how similar the two sequences are: the longer the LCS, the higher the similarity. LCS algorithm · ...