DNA Profiling Methods Research Articles

Qualitative assessment of genotoxicity using random amplified polymorphic DNA: Comparison of genomic template stability with key fitness parameters in Daphnia magna exposed to benzo[a]pyrene.

A method of DNA profiling using the random amplified polymorphic DNA (RAPD) was used to assess toxicant-induced DNA effects in laboratory populations of Daphnia magna exposed to varying concentrations of the genotoxic hydrocarbon benzo[a]pyrene. These effects, represented by changes in the RAPD profiles, were compared with a number of key ecological fitness parameters (age-specific survival, age-specific fecundity, net reproductive rate, and intrinsic rate of population increase). Not only was the RAPD profiling method shown to be a rapid and reproducible assay of toxicant-induced DNA effects, but the qualitative measure of genomic template stability compared favorably with the traditional indices of fitness. The RAPD profiles, however, exhibited higher sensitivity in detecting toxic effects. The significance of these findings for future ecotoxicological studies is discussed.

DNA profiling and plant variety registration. III: The statistical assessment of distinctness in wheat using amplified fragment length polymorphisms

The use of AFLP analysis to produce DNA profiles from a set of 55 wheat varieties, commonly grown in the UK over the past 60 years, is described. Using six different primer pairs, 90 polymorphic bands were readily recognised and recorded. These AFLP bands are not significantly clustered and hence can be used with some confidence, even though they are not mapped. Statistical approaches to the analysis of the data were developed such that the discrimination between the varieties achieved by the use of the six primer pairs, both separately and in combination, could be derived and compared to that achieved by a common set of morphological descriptors. Various criteria for the definition of distinctness in terms of the number of band differences required between pairs of varieties were also compared. In general, higher levels of discrimination were achieved by the inclusion of greater numbers of bands in the analysis. The optimal number of polymorphic bands appears to be between v and 2v, where v is the number of varieties under test. Discrimination levels were adversely affected if the number of bands was below v/2. Distinctness levels achieved by the use of molecular markers can be calibrated so that they reproduce those seen with morphological characters. The results are discussed in relation to the possible use of DNA profiling methods for distinctness, uniformity and stability testing.

ANALISIS DNA MITOKONDRIA SWAB EARPHONE SEBAGAI BAHAN ALTERNATIF PEMERIKSAAN IDENTIFIKASI

Identification include fingerprint, property, medical, dental, serologic and exclusion methods. In the development, identification methods led to molecular forensics, a new field of science evolving since the 1980s, known as DNA fingerprinting.
 Blood spots/bloods, semen spots, vaginal swabs, buccal swabs and bones are specimens widely used in DNA assay for identification. In addition to these specimens, the last objects often used by the perpetrators/victims can be used, such as hearing aids (headsets/earphones). In its use, earphones are attached to the outer ear skin; thus, the earwax is suspected to adhere to the device. To date, in Indonesia personal identification is performed through swabs of earphones/headsets using the DNA profiling method. In particular, mitochondrial DNA has not been widely used for identification.
 The present study was of laboratory experimental. Earphones which have been used for 3 days were placed in room temperature for 1, 7, 14 and 20 days.
 Results showed that the environmental factor of exposure duration had an effect of a significant decrease in the levels of DNA from day 1 to day 20. Only 126-bp mtDNA (HVS II) was detected on the samples of day 1 and continued with sequencing. Mitochondrial DNA has better durability and relatively higher number of copies than those of nuclear DNA. This leads to greater possibility of success in amplification, given the higher number of mitochondrial DNA copies and the fact that mitochondrial DNA is a single locus that allows recombination.