DNA Evidence– ‘Gold Standard’ or ‘Gold-Plated?’

 

 

Bewildered police investigators and prosecuting attorneys who’ve seen  their  “open-and-shut” cases against murderers, rapists and other major felons suddenly vanish in the wake of  “evidence”  purportedly showing a “contradiction” between the DNA of their suspect and the DNA found at the crime scene wonder whether they’ve lost their touch.  A Weizmann Institute of Science team headed by Dr. Dan Frumkin has now proven pretty much beyond doubt that DNA evidence, the touted “gold standard “ of proof in criminal cases, is capable of being fabricated.

 

It probably has been, too. Writing in a recent issue of the prestigious FSI Genetics, Frumkin and Weizmann colleagues Dr. Adam Wasserstrom, Arlane Davidson  and Arnon Grant reported on the relative ease with which they were able to fabricate biological samples containing DNA and, using their access to a DNA profile in a genetic database, construct a DNA sample corresponding to that profile without receiving any biological material from the person to whom the profile belongs.  You don’t have to be a forensic expert to pull this off, Frumkin  avers; a couple of semesters of college-level biology  could suffice. Indeed, he and his co-authors contend, “standard molecular biology techniques…enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized  (artificial) DNA with any desired genetic profile”

 

The fabricators’ next step is to apply their artificial DNA to the surfaces of objects found at the crime scene or to incorporate the bogus DNA into genuine human tissues and plant them in the crime scenes. “Here we show that the current forensic procedure,” the Weizmann Institute scientists submit, “fails to distinguish between such samples of blood, saliva and touched surfaces with artificial DNA and corresponding samples of in vivo generated (natural) DNA.”

 

Does this mean that DNA evidence as a method of identifying criminals is out the window.?  Not necessarily, the Israeli researchers assert. In fact, the Weizmann team has developed a method of authenticating DNA results that draws a line between the natural and artificial product based on “methylation analysis” of certain properties of natural DNA. They’ve successfully employed it on natural and artificial samples of blood, saliva and touched surfaces.  The scientists conclude that crime investigators will need to adopt an “authentication  assay” of this kind in dealing with biological samples at crime scenes or on victims if they intend to maintain the credibility of DNA evidence in the law enforcement system.

 

 

 A Nose that Knows

 

Dr. Hossam Haick’s electronic “nose” can diagnose cancer in a patient in about three minutes flat just by analyzing his breath. Moreover, when completed, the 34 year-old Haifa Technion chemical engineering lecturer’s sniffer will not only provide instant and early malignancy detection, it may even pinpoint on the spot  cancer location in the body.

 

Haick, who developed the sniffer while doing OST-doctoral research at Caltech after getting his doctorate at the Technion,  explains that when a malignant tumor develops in the body, its cells produce chemicals or “biomarkers” that circulate in the blood or urine. They cross from the blood into the lungs, where they’re exhaled in minute, but detectable amounts. His electronic olfactory device, composed of nano-sized sensors, can pick up the scent of these molecules in an instant, thereby giving doctors a potentially significant diagnostic head-start and hugely enhancing the patient’s chances of survival.

 

Under test at the oncology division of Haifa’s Rambam Medical Center, where it has already done instant identification of breast, lung and colon cancer, Dr. Haick’s electronic nose is also exhibiting a potential talent for sniffing out early-stage kidney disease. Noting that malodorous urea is released in the breath of kidney disease patients, a team headed by  Professors Zaid Abassi and Farid Nahoul of the Technion’s Rappaport Medical Faculty created kidney disease in rats and found that Haick’s electronic nose detected the disease in every case, a fact subsequently confirmed by blood and urine tests. The device further underscored its proficiency by detecting 27 other substances in the breath of the sick rates, while giving a control group of uninfected rats a clear bill of health.

 

The importance of identifying type II diabetics with kidney disease at the outset, the Rappaport Medical Center  researchers emphasize, is confirmed by the fact that .later detection may be too late to save the patient and dialysis to clean the blood can cost as much as  $75,000 per year per patient. .Nazareth-raised Hossam Haick appears to have well earned his inclusion in the “TR35” list of scientists chosen from more than 300 nominees by the staff of Technology Review, MIT’s magazine of innovation and his selection as the first Israeli to win the European Union’s Madam Curie Excellence Grant.

 

 

Lahav’s ‘White Cane’

 

That’s what Dr. Orly Lahav  of Tel Aviv University’s Porter School for Environmental Studies calls her joy stick-connected software tool that enables the blind and visually impaired, through a sense of touch, to create cognitive mental maps that give them the ability to “feel out” streets, sidewalks, hallways even navigate inside a shopping center.

 

Formally dubbed “BlindAid,” the device  caused a stir with its recent unveiling at the Virtual Rehabilitation 2009 International Conference at the Carroll Center for the Blind in Newton, Mass. Attendees witnessed  a partially blind woman, after just three sessions of training, effectively navigating a series of real-world target sites wearing a blindfold, after first exploring the virtual environment of the Center, its campus and 10 other sites, including a four-story building.

 

Lahav’s “White Cane” works by stimulating tension, transmitted through the joystick as a  physical sensation, as he first  pre-explores a virtual environment, distinguishing among surfaces like tiled floors, asphalt and grass,  the joystick stiffening as he approaches a virtual wall or barrier. “Our tool lets people ‘see’ their environment in advance so they can walk in it for real,” Lahav  explains.”They can [virtually] ‘feel’ intersections, buildings, paths and obstacles with the joystick…before going out to explore them [in the real-world] on their own” aided by  the mental maps they’ve been able to create.  In theory, she submits, any unknown space, indoors or out, can be virtually pre-explored. after first being mapped out. With existing applications like “Geography Information System,” the information is already in place.