Introduction - Biosensors and Biosensor Kinetics - page 8

quantitative levels of these various reactive species. Enzo Life Sciences claims that these
detection kits:

(1) can also discriminate among superoxides, nitric oxides, and peroxynitrites,

(2) are highly sensitive, specific, and accurate for cell studies,

(3) eliminate nonspecific assay artifacts by using stringent manufacturing conditions,

(4) finally, permits the detection of the different species simultaneously.

Examples of the detection of some of the different analytes in research and clinical labor-
atories have been presented above. They are primarily for the detection of pathogens and
the stages of different diseases, besides attempting, wherever possible, a better understanding
of the different pathophysiological processes involved in the progression of a disease.

However, in a recent editorial, “What's in a test?” in Nature Methods, Evanko (2009)
cautions that customers of genetic and genomic services need better education even more
than tighter regulation. He points out that in the last 3 years there has been a considerable
increase in direct to customer (DTC) services. These provide single-gene tests to companies
that screen customer's DNA for polymorphisms associated with certain diseases. Evanko
(2009) points out that at present even the general public has access to information that was
previously limited to professionals. Tighter regulation is required since concerns have been
raised by public health and consumer advocates as well as by governmental institutions.

Specifically, Evanko (2009) raises the following three issues:

(a) Analytical validity: are the tests accurate?
(b) Clinical validity: are the genetic variants associated with increased disease being tested?
(c) Clinical utility: is the information of use to the customer?

Evanko ( 2009 ) calls attention to the fact that different countries have approached this prob-
lem differently. In the United States there is little Federal oversight and the responsibility
rests with each individual state. In Germany on the other hand, DTC testing, in essence, is
banned. In the United Kingdom, in a recent report on genomic medicine, self-policing by
the industry is recommended. Evanko (2009) opines that the onus is on the customers to
educate themselves about DTC genetic services as to what they offer. For example, he
suggests, that in the case of tests for a single mutation known to be associated with a specific
disease, the customer should examine the details of the science involved.

The Naval Research Laboratory (NRL) (2010) in Washington, DC has developed a sensor
system with assistance from industrial partners for monitoring biomolecules in healthcare,
veterinary diagnostics, food safety, environmental testing, and national security. This is a
highly sensitive, portable biosensor system and is called the Bead Array Counter (BARC).
The NRL system contains an embedded array of giant magnetoresistance (GMR) sensors.