note naturalsciences Right now it is simply a fasta file. Fasta files are for storing DNA sequence information and they are formatted as following. <p>>nameofsequence\n</p> <p>ATCGTACGTTGCTE\n</p> <p>>anothername\n </p> <p>GTCTGT\n </p> <p>so that a line starting with > containing a sequence name is followed by a line containing sequences nucleotide information </p> I am thinking of dredging them in 4 lines a time, because I have reasons to suspect that due to some certain previous operations there might be sequences directly following eachother with different names (on >sequencename\n line) but exactly the same sequence information (on following ATGCTGT\n line). Right now I'm looking to identify and remove such duplicates but I might make use of scripts dealing with many comparision extraction etc. of neighbouring sequences in my files. (Two neigbours means four lines) 1007560 1007643