Leading-edge forensic DNA analyses and the necessity of including crime scene investigators, police officers and technicians in a DNA elimination database.

In recent years, sophisticated technology has significantly increased the sensitivity and analytical power of genetic analyses so that very little starting material may now produce viable genetic profiles. This sensitivity however, has also increased the risk of detecting unknown genetic profiles assumed to be that of the perpetrator, yet originate from extraneous sources such as from crime scene workers. These contaminants may mislead investigations, keeping criminal cases active and unresolved for long spans of time. Voluntary submission of DNA samples from crime scene workers is fairly low, therefore we have created a promotional method for our staff elimination database that has resulted in a significant increase in voluntary samples since 2011. Our database enforces privacy safeguards and allows for optional anonymity to all staff members. We also offer information sessions at various police precincts to advise crime scene workers of the importance and success of our staff elimination database. This study, a pioneer in its field, has obtained 327 voluntary submissions from crime scene workers to date, of which 46 individual profiles (14%) have been matched to 58 criminal cases. By implementing our methods and respect for individual privacy, forensic laboratories everywhere may see similar growth and success in explaining unidentified genetic profiles in stagnate criminal cases.

Morphogenesis during mouse embryonic kidney explant culture.

BACKGROUND: Renal organogenesis is routinely studied using cultured murine embryonic kidneys, but the application of this model has not yet been subjected to rigorous standards. METHODS: We measured ex vivo growth and morphogenesis of day 13 murine kidneys and evaluated the importance of culture conditions and biological variables. RESULTS: Kidney size was measured in two dimensions as planar surface area and was shown to correlate highly with volume (R2 = 0.60, P < 0.005). The final surface area of kidneys was directly dependent on the initial starting size (R2 = 0.61, P < 0.05), suggesting that the final surface area is not a valid outcome measurement unless starting size is equal among treatments. Relative growth rate, defined as (final surface area - initial surface area)/initial surface area, was a good measure of growth and independent of size and anatomical position (P> 0.05). Significant differences in size and growth rates were observed among litters (P < 0.05), implying that kidneys from a given litter must be randomized to avoid confounding results. Planar surface area of each explant increased in proportion to ureteric bud branching (R2 = 0.6854, P < 0.05). In a comparison of a variety of base media and supplements, kidney explants were observed to grow best in Dulbecco's modified Eagle's medium (DMEM)/F12 with 5% fetal bovine serum and to sustain growth for up to 96 hours, despite decreased proliferation and increased apoptosis at this time point. CONCLUSIONS: These results represent an important step in establishing standardized procedures for the use of cultured embryonic kidneys and will improve our ability to apply the model to better understand kidney morphogenesis.