DNA technology in forensic applications

Hochmeister, Manfred N.

doi:10.1016/0098-2997(95)00003-y

Cited by 6 publications

(2 citation statements)

References 189 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The process of forensic stain typing using STR loci roughly consists of three steps: extraction of DNA, PCR amplification, and typing using native or denaturing polyacrylamide gel electrophoresis (PAGE) (1). Until recently these procedures were equally tedious.…”

mentioning

confidence: 99%

Evaluation of an Alkaline Lysis Method for the Extraction of DNA from Whole Blood and Forensic Stains for STR Analysis

Klintschar¹,

Neuhuber²

2000

Journal of Forensic Sciences

View full text Add to dashboard Cite

A modified alkaline lysis protocol for extracting DNA from forensically relevant specimens is evaluated and compared with the chelex 100 method. For whole blood, bloodstains and sperm stains, both methods yielded comparable results after amplification for a pentameric STR locus (HumCD4). The main advantages of the new method are: only approximately ten minutes and two pipetting steps are necessary and the expenses for the extraction are extremely low as only NaOH, TrisHC1 buffer and a single microcentrifuge tube are required. Alkaline lysis also proved to yield DNA suitable for typing longer STRs by using dye-labeled primers and capillary electrophoresis. These advantages should render this protocol especially interesting for high-throughput laboratories in combination with multiplex PCR and fluorescent dye technology, although the storability of the extracts proved to be problematic.

show abstract

mentioning

confidence: 99%

Evaluation of an Alkaline Lysis Method for the Extraction of DNA from Whole Blood and Forensic Stains for STR Analysis

Klintschar¹,

Neuhuber²

2000

Journal of Forensic Sciences

View full text Add to dashboard Cite

show abstract

“…On the other hand, DNA has been shown to be more stable because it has been detected in certain tissue for tens of thousands of years [11]. Additionally, forensic analyses of DNA samples that are decades old are today routine and the DNA remains stable in dried blood stains as long as no bacterial overgrowth occurs [12]. All of these reasons support the use of RNA as a means of determining the age of a biological sample.…”

Section: Why Rna?mentioning

confidence: 99%

RNA analysis as a method to determine the age of a biological sample

Anderson¹

View full text Add to dashboard Cite

RNA Analysis as a Method to Determine the Age of a Biological Sample Stacey E. Anderson DNA analysis by Polymerase Chain Reaction (PCR) allows for the unambiguous identification of the person from whom a biological sample was derived but provides no information about when the sample was deposited. The ability to determine the age of blood or a biological sample would be of significant benefit to the forensic science community. This would provide a temporal linkage between the blood of the perpetuator and the commission of a crime or it could be used to exclude evidence that does not correspond to the time a crime was committed. It was hypothesized that ex vivo RNA decay was a predictable process and real-time PCR indicated that different types of RNA and different sized regions of RNA influenced our capabilities of RNA detection in dried blood stains. The ratio/difference in Ct values between different types and regions of RNA (rRNA vs. mRNA), was identified to change over time in blood stains. Under the conditions examined in the present study, the ratio between the identified RNA species changed in a consistent and reliable way. Environmental influences on RNA detection in dried blood were explored; temperature and humidity both influenced RNA detection but full spectrum light did not. In order to establish a shorter time frame of detection, DNA microarrays were used to identify RNAs that may undergo changes in RNA levels ex vivo due to a stress response. Preliminary results identified several candidate RNA that had up-regulated levels from 4-96 fold in the first 1-4 hours after deposition. Although other approaches have been used in the past to estimate the age of a biological sample, this approach offers the following advantages: DNA and RNA can be co-isolated from the same sample; probes can be made species specific; relatively small samples can be assayed; and, the window of time estimates for dried blood is at least 0 to 150 days. This work provides a starting point for a technique that may prove useful in estimating the age of a biological sample. With the integration of the above mentioned techniques, this method has the potential to solve a problem the forensic community has been investigating for over 100 years.

show abstract