{"id":8853,"date":"2016-07-01T23:19:01","date_gmt":"2016-07-01T23:19:01","guid":{"rendered":"http:\/\/admin.acceleratingscience.com\/behindthebench\/?p=8853"},"modified":"2018-10-18T23:55:38","modified_gmt":"2018-10-18T23:55:38","slug":"flexibility-of-6-dye-chemistries-in-recovering-maximum-information","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/behindthebench\/flexibility-of-6-dye-chemistries-in-recovering-maximum-information\/","title":{"rendered":"Flexibility of 6-dye chemistries in recovering maximum information"},"content":{"rendered":"

Consider an old bone sample that\u00a0is highly degraded or a heterogenous\u00a0sample with high female to male DNA content. It is challenging to obtain useful STR marker<\/a> information from such samples in order to upload to a database and find a match. However, the chances of recovering a quality STR profile are higher when using 6-dye chemistries<\/a>\u00a0that offer superior discriminatory power, maximum sensitivity and high tolerance to inhibition.<\/p>\n

A recent degradation study was conducted by the University of North Texas Health Science Center, Department of Forensic and Investigative Genetics, US, comprising a set of 15 bone samples, including specimens dating back to the late 19th<\/sup> century. The bone sample extracts were analyzed using the\u00a0Applied Biosystems\u2122 GlobalFiler\u2122 chemistry<\/a> as well as a competitive STR chemistry. Overall, samples processed using the GlobalFiler kit<\/a> showed better allele recovery than results from the competitive chemistry which exhibited more drop-out\/allele loss.\u00a0\u00a0 For the male bone samples, analyzed with an analytical threshold as low as 50 RFU threshold, all male markers were recovered using the GlobalFiler\u2122 kit<\/a> while results from the competitive chemistry exhibited loss of the rapidly mutating Y-marker positions.<\/p>\n

Thus, even within the available set of 6 dye technologies, assessing STR kit performance on real-world samples becomes important when selecting the right chemistry.<\/p>\n

Dr. Antonio Alonso, a DNA expert at the National Institute of Toxicology and Forensic Sciences, Madrid (Spain), in a recent interview, stresses the need for forensic laboratories to make that transition to 6-dye chemistries in order to gain workflow efficiency and reduce operating costs. He further highlights the value of Y-STR analysis in resolving sexual assault<\/a> cases and provides the example of an 18-year old rape-murder cold case in Spain that was solved using Yfiler\u2122 Plus<\/a> chemistry.<\/p>\n