Fingerprints and Liquid Nitrogen

[starsplitter7]

Hi there,

I am a new CST in Florida.

I wanted to verify that using liquid nitrogen or dry ice to pull tape apart will not interfere with DNA. (I have previous experience with LN and DI, so I have experience handling both).

Does anyone have a preferred method? Liquid Nitrogen, Dry Ice, or another method to pull tape apart that will not interfere with DNA.

Once the tape is pulled apart, I have used Sticky Side Powder and Crystal Violet to develop the prints.

Thank You, Tanja. (P.S. I did do a quick search in the forum to see if the question had been asked and I couldn't find it, so I apologize if I am bringing up a common question.)

[Michele]

I’ve put tape in a refrigerator or freezer and that seems to work fine. I don’t have any personal knowledge about DNA but I’ve been told that it degrades faster with extreme changes in temperature. If that's true then it seems like a regular freezer would affect the DNA less than liquid nitrogen or dry ice.

For processing the tape, I’m sold on wetwop. Once I tried it, I’ve never gone back to the other methods (except to show people how much better the results are with wetwop).

[starsplitter7]

Thank you so much for replying. I appreciate your input. I like Wetwop along with Sticky Side Powder.

[mdavis]

My best results have been to use glue fuming in a vacuum chamber, followed by fluorescent dye staining, usually a mix of Ardrox, BY40 and sometimes R6G in either an ethanol or water carrier. It doesn't seem to matter much how the tape is separated. Adhesive to adhesive bonds are almost always a loss. The more slowly you pull the tape, the less damage there is to the adhesive layer during removal and the less likely you will separate the adhesive layer from its backing or disrupt the integrity of the adhesive surface. It also depends on the quality and brand of tape (duct tape for example varies widely) as to how well the adhesive layer is bonded to the backing, how substantial the cloth mesh is, and how much damage is done in removing it from various surfaces. I have not had much luck with wet-powder methods, although some earlier experiments did show that the brand of powder gave differing results with various wetting agents.

[kevin]

been finding that sticky side will sometimes develope prints on the non-adhesive side alot of the time. I'm sure it is just transferred adhesive residue in most cases, but CA won't catch it and I stay away from dye staining it. Tends to happen with heavy adhesive like duct tape and not so much on a plastic, clear or electrical. Sticky side works best for me, but I think liqi nox would work well too.