Rates of success of DNA extraction from non-standard samples. In the first part of this article, we saw some unusual methods to obtain DNA of an individual for the purpose of DNA testing. In this article, we will see the success rate of extraction of DNA of various types of samples and as they may vary from one to another. Non-standard samples do not always guarantee the obtaining of a DNA profile. Even with the use of oral cotonetes it is possible to not obtain DNA, as in some cases where oral skived has not been adequately made or to the cotonetes growing them rust by storage conditions wet, in general, with this type of sampling problems are less than 2% – therefore, and depending on the nature of the sampleusually relates to him a degree of high, medium or low probability of success in extraction of DNA from each sample (in some cases, provided a percentage of probability of success) high (80%): for samples such as fresh stains of blood or hair with root, where, for a laboratory DNA qualified and with experience, the DNA extraction is performed without complications. In such cases, and provided sample have been handled properly in his later sending, as well as collection one can expect a high degree of probability of success in the extraction of DNA. Half (50%-60%): for samples such as toothbrushes or cigarette ends success is influenced by a number of variables, including quantity of use and/or storage conditions. Therefore, a cigarette butt completely smoked cigarette, which is located in an ashtray at home, has more chance of success of DNA extraction than a cigarette smoking and found on the street and partially exposed to the elements (e.g.
rain). Low (20% 30%) For specimens such as bone or teeth, where the extraction of AND is a complicated process and requires much time, these should be normally handled by a highly specialized laboratory. In these cases, it is recommended that individuals consult with the laboratory the degree of experience, if acceptance of the sample and its cost. The classification described above is only a guide, since as we have seen, what is important is not only the type of specimen, but that also other variants that may influence, such as: 1. not appropriate (eg storage conditions. Moist environment, excessive heat, etc.) 2. Improper sample handling (contamination with another sample of DNA or earth touching the sample) 3.
Presence of insufficient DNA (eg. A toothbrush frequently used vs. one used only once) is also important to mention that the success rate will depend largely on the ability of the laboratory performing the test. Not all laboratories that can perform a DNA paternity test with oral cotonetes are able to extract AND by other means – between more difficult medium (eg. Bone and tooth), greater degree of expertise and experience are required to increase the chances of a successful DNA extraction. Finally, it is also important to mention once again that with samples not standard there is a risk that the removal does not work. Therefore, a person who is considering the dispatch of such shows, especially where there is only a limited amount of sample, (eg. By that the person died) should consider this. The selection of a laboratory experienced (with possible forensic specialization) will minimize this risk. Original author and source of the article.