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RAM fingerprint chemical processing
Posted: Thu Apr 15, 2021 5:38 pm
by shiinale18
Hi!
I'm attempting to revamp our lab and was wondering if about a few things. Does anyone here still use RAM and how do you feel about it?
What other chemicals do you use or just processing methods in general. Also, I was told that with RAM, you have to wait at least 4 hours before you could look at it, is this accurate?
Thanks!
Re: RAM fingerprint chemical processing
Posted: Fri Apr 16, 2021 7:54 pm
by ekuadam
The lab I work in for non porous items we use superglue and Rhodamine 6g. We also have basic yellow if we want to use it. Along with powder if we choose.
For porous items we use indanedione and ninhydrin.
Other chemicals we have are:
Amido Black
LCV
Gentian Violet
Wet Wop
Acid Yellow
ThermaNin
SPR
As far as your RAM question, I haven’t ever used it so I can’t speak to how long you have to wait.
I don’t think I’m missing anything. I would like to look into incorporating the ZnCL mixture for Indanedione when I have chance. Maybe we will get an intern this summer that can help me out. Haha.
Re: RAM fingerprint chemical processing
Posted: Mon Apr 19, 2021 7:28 am
by josher89
RAM is a mixture of dyes so you have a greater spectrum of wavelengths to visualize. In my opinion, it's not as sensitive as the individual dye.
We also use R6G and a 532nm (green) laser to visualize. We have BY as a backup for reddish backgrounds (Solo cups, gas cans, etc.) but have to pull out a blue ALS for visualization - the downside of R6G is that it doesn't give great fluorescence on reddish backgrounds.
Find something that works and don't change it. We've used R6G for at least 10 years as our primary dye and have never felt like we are missing out on other stains.
For porous, our go-to is ninhydrin. We also have DFO which works great (and we'd use first before nin) and we also have IND/ZnCl as an option as well. If it's a busy piece of evidence, we'll sequence it otherwise, nin is the first (and last).
Bottom line, you don't need fifty options - usually a couple for each type are sufficient enough - any more than that and the "juice isn't worth the squeeze" (trademarked by JB)
Good luck!
Re: RAM fingerprint chemical processing
Posted: Mon Apr 19, 2021 8:58 am
by Texas Pat
josher89 wrote: ↑Mon Apr 19, 2021 7:28 amWe have BY as a backup for reddish backgrounds (Solo cups, gas cans, etc.) but have to pull out a blue ALS for visualization - the downside of R6G is that it doesn't give great fluorescence on reddish backgrounds.
As a Luddite from the Twentieth Century who learned image capture on an MP-4, the first thing I thought of was how great superglue would have been on a solo cup, photographed using the old type of CPO (contrast process ortho) blue sensitive film would be with a massive overexposure of white light. That should have given a very clean white fingerprint on a black background. Those old cameras with a variety of different films and filters were sometimes better than anything done today with fluorescence and a 35mm camera.
A line quoted twice in the movie Skyfall was this:
First, early in the movie when Eve Moneypenny is shaving Bond with a straight razor, she remarks "Sometimes the old ways are the best."
Then late in the movie, Kincade, the caretaker at Skyfall castle lays a knife on the table, which Bond eventually uses to kill Raoul Silva, Kincade says exactly the same line, "Sometimes the old ways are the best."
I think in the rush to obsess over technology, we sometimes forget that.
Key word: "Sometimes."
Re: RAM fingerprint chemical processing
Posted: Mon Apr 19, 2021 9:13 am
by ekuadam
josher89 wrote: ↑Mon Apr 19, 2021 7:28 am
RAM is a mixture of dyes so you have a greater spectrum of wavelengths to visualize. In my opinion, it's not as sensitive as the individual dye.
We also use R6G and a 532nm (green) laser to visualize. We have BY as a backup for reddish backgrounds (Solo cups, gas cans, etc.) but have to pull out a blue ALS for visualization - the downside of R6G is that it doesn't give great fluorescence on reddish backgrounds.
Find something that works and don't change it. We've used R6G for at least 10 years as our primary dye and have never felt like we are missing out on other stains.
For porous, our go-to is ninhydrin. We also have DFO which works great (and we'd use first before nin) and we also have IND/ZnCl as an option as well. If it's a busy piece of evidence, we'll sequence it otherwise, nin is the first (and last).
Bottom line, you don't need fifty options - usually a couple for each type are sufficient enough - any more than that and the "juice isn't worth the squeeze" (trademarked by JB)
Good luck!
I agree. As long as the chemicals work good you don't need a bunch. My first processing job we used Physical Developer after NIN. I didn't think it worked well. Plus you had to figure out how to navigate not ripping paper apart moving it in and out of 4 different chemicals.
As far as BY40, I had orange pill bottles recently as well as a bright orange "NIKE" shopping bag. It worked great on those. Where as R6G would have just been washed out.
Re: RAM fingerprint chemical processing
Posted: Tue May 11, 2021 8:15 am
by rsc55
The lab I used to work in validated both RAY and RAM. I don't recall ever waiting prior to visualizing, other than the normal drying time. A vast majority of us preferred RAY over RAM, though, and I don't think we ever made RAM again after the validation. RAY was our go-to.
Re: RAM fingerprint chemical processing
Posted: Tue May 11, 2021 6:37 pm
by Ernie Hamm
In my Index File (part of Legacy link at CLPEX) there are a few articles on the use of RAM. One that may be of interest addresses safety concerns associated with RAM. It was written by Laura Tierney in JFI, 59:3 (2009). BTW, when you open the Index, you can use Excel search for the "Comment" column by entering "_RAM_" for the search term. The spacing before and after RAM are necessary or you will get any reference having "ram" in a word in the various comments on other articles.