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Latent Print Examination » Questions from FP Experts for FP Experts... Processing, Testimony, and Technical Matters » Rhodamine on Baggies- leaving spots!! « Previous Next »

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L (Unregistered Guest)
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Posted From: smtpout.hayward-ca.gov
Posted on Thursday, February 10, 2011 - 11:31 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks. It doesn't seem like a problem with the CA process, as it only happens with baggies and none of the other items. I actually spoke to some other experts in the area and they also advised a rinse, but with methanol (since I use methanol based R6G usually). I tried that and it seemed to help with the raindrop appearance :-) Now if only someone could make the fingerprints appear everytime and make baggies easier to process...hmmmmm.
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Andrew Reitnauer (Areitnau)
Member
Username: Areitnau

Post Number: 23
Registered: 06-2007
Posted on Tuesday, January 25, 2011 - 09:51 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Just off the top of my head, is the humidity level correct during the CA process? Excess humidity could cause condensation, resulting in CA depostion. Also, you may want to try rinsing the item with distilled water after the R6G treatment. It may remove any excess dye that may be collecting and drying.
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Lisa K (Lisak1981)
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Username: Lisak1981

Post Number: 1
Registered: 01-2011
Posted on Saturday, January 22, 2011 - 09:36 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi everyone! I have been having continuous problems while processing baggies (usually sandwich baggies, but sometimes grocery bags, ziplocs, or saran wrap- often from drug cases).

I always examine the item, then superglue in the vacuum chamber. I usually re-examine the item, but I have found that the vacuum chamber leaves so little residue that I NEVER see anything!

I will then dye stain using Rhodamine 6G (methanol based)...I usually spray the baggies with a light stream of R6G, but occassionally I will dip them. I will then hang them in the fume hood to dry. Almost EVERYTIME I examine the baggies under the ALS all I see is spots of R6G...the solution dries incredibly spotty (to the point that the entire bag looks like it's covered in glowing raindrops)and obliterates the chance of anything every being recovered! I don't want to risk destroying potential prints with my dye staining!

I am not sure if the airflow in the fume hood is too high or if there is something wrong with my R6G soultion...but it's driving me insane!

Has anyone else experienced this??
Also, how much of a success rate do you have on recovering prints on baggies?
Hopefully someone has a solution for me?!?

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