Detect fingerprint by laser: treated ... Log Out | Topics | Search
Moderators | Register | Edit Profile

Latent Print Examination » Miscellaneous Postings » Detect fingerprint by laser: treated by rhodamine 6G « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Administrator (Admin)
Moderator
Username: Admin

Post Number: 43
Registered: 07-2006
Posted on Sunday, December 30, 2012 - 06:02 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

After cyanoacrylate (superglue) fuming, Rhodamine 6G (R6G) is often applied in an alcohol solution (methanol, ethanol, etc.) and soon afterwards the surface bearing the cyanoacrylate polymer is rinsed a second time with clean (no Rhodamine dye) alcohol to remove the excess background staining.

After drying, excitation with any of a variety of relatively monochromatic light sources works well, with viewing and photography through anti-laser goggle filters blocking the wavelength of excitation light. Even inexpensive relatively monochromatic LED lights can often work quite well, without the need for expensive Nd:YAG (frequency doubled), Argon Ion (both 488 and 514.5 nm), Copper Vapor (511 nm), etc., laser excitation.

There are also other methods, with some folks preferring a weaker one-step solution of R6G in alcohol, and even mixing with multiple fluorescent dyes (e.g., the RAM solution).
Top of pagePrevious messageNext messageBottom of page Link to this message

Nguyen Lam (8s0nc1)
Member
Username: 8s0nc1

Post Number: 1
Registered: 12-2012
Posted on Friday, December 14, 2012 - 10:35 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Dear friends,
Please help me solve this problem:
After collecting the fingerprints by means of cyanoacrylate (CA) fuming, I dyed with rhodamine 6G. In the process of Fuming, white polime form on fingerprint clearly. However, after dying, the dye overlap fingerprint and spread out over the area which have not pattern (print). At this time, we can not see fingerprint clearly . Is the dye too dense? So how do I solve this problem? Can I use laser 532 nm to illuminate this Rhodamine 6G dyed fingerprints?
Thank you so much.

Add Your Message Here
Post:
Username: Posting Information:
This is a public posting area. Enter your username and password if you have an account. Otherwise, enter your full name as your username and leave the password blank. Your e-mail address is optional.
Password:
E-mail:
Action: