User:Meganmwolf/sandbox

Ninhydrin

A ninhydrin solution is commonly used by forensic investigators in the analysis of latent fingerprints on porous surfaces such as paper. Amino acid containing fingermarks, formed by minute sweat secretions which gather on the finger's unique ridges, are treated with the ninhydrin solution which turns the amino acid finger ridge patterns purple and therefore visible.

'''To further enhance the ability of ninhydrin, 1,2-indanedione-ZnCl (IND-Zn) can be used on the question material first. A study, conducted in 2015, found that this was the best order because the weakening of bonds from the IND-Zn allows for increased reactions with ninhydrin.'''

Add subheading of 'Fingerprints' under uses

'''Janssen-Bouwmeester, along with other collogues, conducted a study in which they created positive control tests for fingerprint development reagents, one of which was ninhydrin. In this study, the shelf life for these controls was tested. The best conditions for the control tests with ninhydrin were: store in the freezer and keep for 6 months at the most.'''

Fingerprint Powder

Add Image of Fingerprint

Further Applications/Uses
'''Fingerprint powder is useful for the detection and collection of latent fingerprints, but that is not all the analysis that can be done. Kaplan-Sandquist, LeBeau, and Miller conducted a study where they tested fingerprint development methods with the MALDI/TOF MS.(add link) The fingerprint powder was found to be useful as a MALDI matrix. This instrument can identify many compounds. In the study, fingerprints tested contained known solvent residues. The fingerprint powder along with the MALDI matrix had the highest average detection rates of (88%). Since this study was controlled, it is known that the use of this further application with the MALDI/TOF MS would be effective.'''

Thermal decomposition

Practical Applications
'''There are many scenarios in the real world that are affected by thermal degradation. One of the things affected is fingerprints. When anyone touches something, there is residue left from the fingers. If fingers are sweaty, or contain more oils, the residue contains many chemicals. De Paoli and her collogues conducted a study testing thermal degradation on certain components found in fingerprints. For heat exposure, the amino acid and urea samples started degradation at 100°C and for lactic acid, the decomposition process started around 50°C. These components are necessary for further testing, so in the forensics discipline, decomposition of fingerprints is significant.'''

Immunolabeling

Further Applications
'''Research has been conducted to test the compatibility of immunolabeling with fingerprints. Sometimes, fingerprints are not clear enough to recognize the ridge pattern. Immunolabeling may be a way for forensic personnel to narrow down who left the print. Researchers conducted a study which tested the compatibility of immunolabeling with many developmental techniques for fingerprints. They found that indanedione-zinc (IND-ZnCl), IND-ZnCl followed by ninhydrin spraying (add link) (IND-NIN), physical developer (PD), cyanoacrylate fuming (add link) (CA), cyanoacrylate followed by basic yellow staining (CA-BY), lumicyanoacrylate fuming (Lumi-CA) and polycyanoacrylate fuming (Poly-CA) all were compatible with immunolabeling. Immunolabeling can not only extract donor profiling information from fingerprints, but can also enhance the quality of the fingerprints which would both be beneficial in a forensic case.'''

Secondary ion mass spectrometry

In Applications section:

'''SIMS can be used in the forensics field to develop fingerprints. Since SIMS is a vacuum based method, it is necessary to determine the order of usage along with other methods of analysis for fingerprints. This is because the mass of the fingerprint significantly decreases after exposure to vacuum conditions.'''