For Y-DNA and mtDNA, store the raw results that you get, plus the haplogroup.

- Y-DNA results are the marker names and their values.  ex: DYS393=12

- mtDNA results are the position where you differ from the Cambridge Reference Sequence (CRS) plus the base (letter) that you have.  ex: 16519C.

For autosomal DNA, you'll need to store the complete raw data file.  It's a huge file, so you can't just enter the data into a family tree program.

Some family tree programs now have fields for Y-DNA and mtDNA results, so check to see if your program has them before creating custom fields.