This was used when I first taught 7th grade as a little lab for students who needed a hands on experience to see the look of the DNA strand.
I haven't really looked at it since then - maybe 10-12 years now. I know that they enjoyed this activity (except having to write a paper with it).
I have it at a low price because it is so old and I have not revisited it in many years.
Like all things, it is editable and you can change and adapt it to the classroom you have.