Hi,

I am trying to use the regular expressions to check if the input value has any characters other than T,C,G and A. I am using the following expression

[a-z-[bdefhijklmnopqrsuvwxyz]]*|[A-Z-[BDEFHIJKLMNOPQRSUVWXYZ]]*

But it only allows one character "T" to pass others fail sor t will check ok but  TCGA or TC or TCGAGACT fails. Any ideas about how to construct the expression so the string is passed if only contains T,C,G and A. It should fail if it conatins any other characters.

Thanks

Try this:     [T|C|G|A]*

FYI:

Thanks a million.

Do you have an example on how to return only [A|T|C|G] from a long string of characters? For example if yo have

 1. aagtcctgcttc 2.agtctccttc

It would return

aagtcctgcttcagtctccttc

Hence removing all characters other than ATCG? 

string Test = "1.atgc2.gtcg98#sl";
System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex("[^atcgATCG]{1,}");
string result = regex.Replace(Test, "");
Console.WriteLine(result);