1.3 Purpose of Study
The purpose of this study is to evaluate various types of packaging material and
their suitability for wet biological samples by determining if the container causes the
sample to be susceptible to degradation and if the packaging is able to fully contain wet
biological evidence (i.e. does not permit the fluid to soak through to the exterior). The
packaging must be suitable for the evidence to be transferred from the scene of a crime to
a laboratory and stored until processing takes place. As is evident from the guidelines
mentioned earlier, one of the major concerns in packaging biological evidence is the ability
for that evidence to dry (1, 3). It is known that moisture is a factor in decomposition (5) of
biological materials and that water plays a large role in DNA degradation (6-9). Therefore,
if a wet biological sample is packaged in a material that will not allow for such moisture to
expel, it could be detrimental to the evidence.
Degradation of DNA is not the only concern for the preservation of biological
evidence because multiple techniques are used to identify the presence of a biological fluid
prior to DNA testing. Many samples are subjected to presumptive screening, secondary
screening, and confirmatory tests for body fluid identification, thus the stability of these
identification methods was assessed prior to DNA analysis. Additionally, this study