Category Archives: DNA

Virology 2015 Lecture #8: Viral DNA Replication – Video

Posted: Published on February 28th, 2015

Virology 2015 Lecture #8: Viral DNA Replication No DNA virus can replicate its genome independent of the host cell, but some are more independent of others. In this lecture we cover how DNA viruses replica... By: Vincent Racaniello … Continue reading →

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Untangling DNA with a droplet of water, a pipet and a polymer

Posted: Published on February 28th, 2015

Researchers have long sought an efficient way to untangle DNA in order to study its structure -- neatly unraveled and straightened out -- under a microscope. Now, chemists and engineers at KU Leuven, in Belgium, have devised a strikingly simple and effective solution: they inject genetic material into a droplet of water and use a pipet tip to drag it over a glass plate covered with a sticky polymer. The droplet rolls like a ball over the plate, sticking the DNA to the plate surface. The unraveled DNA can then be studied under a microscope. The researchers described the technique in the journal ACS Nano. There are two ways to decode DNA: DNA sequencing and DNA mapping. In DNA sequencing, short strings of DNA are studied to determine the exact order of nucleotides -- the bases A, C, G and T -- within a DNA molecule. The method allows for highly-detailed genetic analysis, but is time- and resource-intensive. For applications that call for less detailed analysis, such as determining if a given fragment of DNA belongs to a virus or a bacteria, scientists opt for DNA mapping. This method uses the longest possible DNA fragments to map the DNA's 'big … Continue reading →

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Attorney: DNA untested in rape conviction

Posted: Published on February 28th, 2015

WORCESTER -- A superior court judge will decide if a former Fitchburg man serving 32-41 years for two separate child rapes will be granted a new trial to challenge the DNA results used as evidence in his first conviction in 2006. Roy Dumas, 58, handcuffed and dressed in standard prison garb, appeared Thursday before Superior Court Judge Richard T. Tucker with his attorney, Edward Gauthier, to request a new trial. Gauthier argued that during Dumas' first trial in 2006, the forensic expert who testified that Dumas' DNA matched that found on the victim did not actually test the DNA sample used to convict him. Gauthier also said the victim never did positively identify Dumas as her attacker because a bag was put over her head before the sexual assault. He also said Dumas presented an alibi defense that he was seen by at least three witnesses in another part of the state during the time of the assault. "The nail in the coffin was the DNA evidence. It was the strongest part of the case," said Gauthier. Dumas, said Gauthier after the hearing, was denied the right to cross examine the technician who tested the sample of his DNA during … Continue reading →

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