Biomedical subjects

Hanna Andréasson

Publications and source records attributed to Hanna Andréasson.

3 recordsLinked to original sources

PubMed2005

Mitochondrial D-loop and coding sequence analysis using pyrosequencing.

In forensic casework analysis, mitochondrial deoxyribonucleic acid (DNA) often is used when the evidence material contains scarce amounts of DNA. Here, a mitochondrial DNA typing system for D-loop and coding region analysis based on pyrosequencing is described. Pyrosequencing is a real-time, single-tube sequencing-by-synthesis method, in which a cascade of enzymatic reactions yields detectable light. This pyrosequencing system has a higher resolution than the D-loop analysis performed routinely today as it also covers informative positions in the mitochondrial coding region. The system is composed of 16 polymerase chain reaction (PCR) fragments and 24 pyrosequencing reactions with a turn around time for a 96-well plate of less than 3 h after PCR.

Base Sequence↗

PubMed2003

Rapid quantification and sex determination of forensic evidence materials.

DNA quantification of forensic evidence is very valuable for an optimal use of the available biological material. Moreover, sex determination is of great importance as additional information in criminal investigations as well as in identification of missing persons, no suspect cases, and ancient DNA studies. While routine forensic DNA analysis based on short tandem repeat markers includes a marker for sex determination, analysis of samples containing scarce amounts of DNA is often based on mitochondrial DNA, and sex determination is not performed. In order to allow quantification and simultaneous sex determination on minute amounts of DNA, an assay based on real-time PCR analysis of a marker within the human amelogenin gene has been developed. The sex determination is based on melting curve analysis, while an externally standardized kinetic analysis allows quantification of the nuclear DNA copy number in the sample. This real-time DNA quantification assay has proven to be highly sensitive, enabling quantification of single DNA copies. Although certain limitations were apparent, the system is a rapid, cost-effective, and flexible assay for analysis of forensic casework samples.

Amelogenin↗

PubMed2002

Real-time DNA quantification of nuclear and mitochondrial DNA in forensic analysis.

The rapid development of molecular genetic analysis tools has made it possible to analyze most biological materialfound at the scene of a crime. Evidence materials containing DNA quantities too low to be analyzed using nuclear markers can be analyzed using the highly abundant mtDNA. However, there is a shortage of sensitive nDNA and mtDNA quantification assays. In this study, an assay for the quantification of very small amounts of DNA, based on the real-time Taq-Man assay, has been developed. This analysis will provide an estimate of the total number of nDNA copies and the total number of mtDNA molecules in a particular evidence material. The quantification is easy to perform, fast, and requires a minimum of the valuable DNA extracted from the evidence materiaL The results will aid in the evaluation of whether the specific sample is suitable for nDNA or mtDNA analysis. Furthermore, the optimal amount of DNA to be used in further analysis can be estimated ensuring that the analysis is successful and that the DNA is retained for future independent analysis. This assay has significant advantages over existing techniques because of its high sensitivity, accuracy, and the combined analysis of nDNA and mtDNA. Moreover, it has the potential to provide additional information about the presence of inhibitors in forensic samples. Subsequent mitochondrial and nuclear analysis of quantified samples illustrated the potential to predict the number of DNA copies required for a successful analysis in a certain typing assay.

Cell Nucleus↗