A fluorescent microscopy-screening test for efficient STR-typing of telogen hair roots.

Nuclear DNA-profiling from human hairs is a well-known technique in forensic investigations, but its success rate is quite low with some hair types. As nuclear DNA (nuDNA) extracted from telogen hair roots is in short supply and is often degraded, a simple and effective method of estimating the number of nuclear DNAs in telogen roots has been developed. DAPI, a fluorescent, non-destructive DNA stain, allows the visualization of "nuclei" (DAPI-positive spots the shape and size of the human follicular cell nuclei) and does not interfere with subsequent PCR analyses. We stained 3242 telogen roots from 27 donors. Surprisingly, of the 2572 club roots without any soft tissue remnants 11% contained visible "nuclei" and 3.3% even contained many. At the same time 57% of the 670 telogen roots with soft tissue remnants did not show any fluorescent "nuclei". We analysed the STR-profile of some of the roots selected by the DAPI screening, i.e. 132 telogen roots without soft tissue remnants, with a success rate of 79%. Our proposed screening method allows the DNA laboratory to analyse nuclear DNA only in the most promising hair roots.

Toxicological data and growth characteristics of single post-feeding larvae and puparia of Calliphora vicina (Diptera: Calliphoridae) obtained from a controlled nordiazepam study.

Larvae of the Calliphora vicina (Diptera: Calliphoridae) were reared on artificial food spiked with different concentrations of nordiazepam. The dynamics of the accumulation and conversion of nordiazepam to its metabolite oxazepam in post-feeding larvae and empty puparia were studied. Analysis was performed using a previously developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. This method enabled the detection and quantitation of nordiazepam and oxazepam in single larvae and puparia. Both drugs could be detected in post-feeding larvae and empty puparia. In addition, the influence of nordiazepam on the development and growth of post-feeding larvae was studied. However, no major differences were observed for these parameters between the larvae fed on food containing nordiazepam and the control group. To our knowledge, this is the first report describing the presence of nordiazepam and its metabolite, oxazepam, in single Calliphora vicina larvae and puparia.