OK, so I know you have seen the "01001100" binary thread and such.
And I know you brilliantly devised the fogglethorpe decoder.
So heres the gist of the idea.
First you convert your text into base 4 math, like we were converting to binary, octal, hex, and such. I have searched, and couldn't find an ASCII to base 4 math converter. A message would end up looking like this "103020100203010" or something similar.
Now you assign one of four letter combinations to 0,1,2, and 3. The letters are well known. A, C, G, and T. Its the DNA nucleotides. Except that they can only occur in pairs. AT, TA, CG, GC are the only pairs possible. So for this example, 0=AT, 1=TA, 2=CG, and 3=GC.
Most have seen the DNA sequencing strings such as "ATCGCGTACG" and so on.
So the idea is to encode a text message first to base 4, then to the nucleotide pairs so that it appears as if it is a segment of DNA.
I will let you now speculate on the possibilities here. Interested?
(Implanting secret messages in mantis DNA.........hmmmmm.)