FLUORESCENCE EXAMINATION

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Technique Name:
Fluorescence Examination
Surface Used On:
Non-Destructive for all surfaces.
Sensitive To:
Absorption/Emmittence of various light wavelengths.
Development Color: Method to Record: Hazard: Protective Clothing: Fume Hood Use:

N/A

Eye Damage

Eye Protection

Not
Reagent Characteristics

Development Complete When:

Source of Error:

Incompatibilities:

Precautions:

Storage Container:

Safety:

Recommendations:


Similar Reagents



Sequential Reagents
(Not necessarily in this order.)



FLUORESCENCE EXAMINATION :
USED FOR:

1. Luminescence of natural 
   components in latent print residue.
2. Fluorescent fingerprint powders.
3. Fluorescent dye stains.
4. Darkening blood impressions.
5. Fluorescing fluids for refrigerants,
   transmissions, fuels and coolants.
6. Fluorescent physiological fluids.
7. Luminesces backgrounds for 
   contrast improvement.

CENTERED WAVELENGTHS:

A. 300 nm to 400 nm
Fluorescing U-V sensitive 
powders or dyes.
Fluorescing physiological fluids.
Ardrox excitation.


B. 400 nm to 450 nm
R.A.Y. excitation.
Absorbing blood\bite mark detail.
Fluorescing physiological fluids.


C. 455 nm to 515 nm
Searching on non-fluorescent
backgrounds.
Basic Yellow 40 excitation.
Zinc chloride excitation.


D. 550 nm to 590 nm
Searching on highly 
fluorescent backgrounds.
DFO excitation.
PROCEDURE OF APPLICATION

A. 
Reduce ambient light.
B. 
Aim the light from the
Forensic Light Source.
C.
View the item using 
Yellow, Red or Orange
colored goggles.
D.
Photograph detail using
colored fiters similar to 
the viewing goggles.


Ridge Detail Visualized by:

Forensic Light Source induced.


Reagent Applicabilities:

Non-Destructive
Porous sufaces
Non-Porous surfaces


Other Name(s):

Alternate Light Source
Forensic Light Source
Laser


Process Summary:
A non-destructive technique to note the presence of visible detail. Several models of Forensic Light Sources are available, most of which provide an excitation wavelength range from 350 nm to 600 nm. Improved viewing of the ridge detail is accomplished either by rendering the ridge detail darker upon viewing in an absorbtion mode, or, through fluorescence of the ridge detail which is either rendered luminescent when exposed to the light, or made fluorescent by the addition of chemicals. Orange, Red or Yellow viewing barrier filters (viewing goggles) are used for viewing or during photography of the detail. The goal of Fluorescent examinations is to achieve the maximum fluorescence of the ridge detail with the minimum of background fluorescence/reflection.
Accepted Deviations:
Adjusting the wavelength of the light source may produce better visualization results. Different manufacturers produce products that provide excitation wavelengths at different pre-selected wavelengths, and over different wavelength range.
Supporting Reference Materials:
1. Advances in Fingeprint Technology 2nd. Ed., Lee, H.C. & Gaensslen, R.E., CRC Press, Boca Raton, FL., 2001.
2. Manual of Fingerprint Development Techniques 2nd. Ed., Home Office - Police Scientific Development Branch, White Crescent Press, Ltd., Luton, England, 2001.

Return to: Main Page   ||  Porous Surfaces  ||  Non-Porous Surfaces  ||  Fluorescent Techniques  ||  Non-Destructive  ||  Post-Cyanoacrylate  ]