Tag Archives: PROOF

Diagnostics on a credit card?

Diagnostic equipment keeps getting smaller with the latest being the size of a credit card (more or less). It’s called an ‘mChip’ and can be used to diagnose either HIV or syphillis. From the August 2, 2011 article by Ariel Schwartz on Fast Company,

If you were concerned you had HIV (and lived in America), it would be easy enough to get some blood drawn at a clinic near your house, and wait a few days (or even hours) for the results. But in Africa, many clinics and hospitals have to send out blood samples to a national lab. It’s a process that can take weeks, and patients in remote areas sometimes don’t even bother to make the trek back to the clinic to get results. On a continent with a rampant HIV epidemic, this is a big problem. But Columbia University researchers have a partial solution–a $1 plastic chip that can diagnose HIV and syphilis in 15 minutes.

The “mChip”, a credit-card-sized piece of plastic that is produced using a plastic injection molding process, tests for multiple diseases with just one pinprick of blood.

The international team working on this project was led by professor of bioengineering at Columbia University, Samuel Sia. Field testing of the mChip took place in Rwanda. GrrlScientist in her August 3, 2011 posting (at the Guardian Science blogs site) offers more technical details,

“The microfluidic design is very simple”, said Dr Sia. “It’s essentially a .. linear channel that’s been looped around in various ways.”

… This credit card-sized cassette is manufactured from plastic and each mChip cassette can test seven samples (one per channel), and requires no moving parts, electricity or external instrumentation. Instead, it has small holes moulded into the plastic so reagent-loaded tubes can be attached. …

The principles for how the mChip work are well known, straightforward and, quite frankly, beautiful.

The mChip can be used for other diagnostic tests. A prostate cancer testing mChip has already been approved for use and other tests are being developed as well.

Sia’s team is not the only one working on faster, cheaper, more reliable diagnostic tests. A team at the University of Georgia (US)  has just published research about their flu detection test (from the August 3, 2011 news item on Nanowerk),

A new detection method developed at the University of Georgia and detailed in the August edition of the journal Analyst (“One-step assay for detecting influenza virus using dynamic light scattering and gold nanoparticles”), however, offers the best of both worlds. By coating gold nanoparticles with antibodies that bind to specific strains of the flu virus and then measuring how the particles scatter laser light, the technology can detect influenza in minutes at a cost of only a fraction of a penny per exam.

“We’ve known for a long time that you can use antibodies to capture viruses and that nanoparticles have different traits based on their size,” said study co-author Ralph Tripp, Georgia Research Alliance Eminent Scholar in Vaccine Development in the UGA College of Veterinary Medicine. “What we’ve done is combine the two to create a diagnostic test that is rapid and highly sensitive.”

Sia’s team seems to have worked on both the test and diagnostic device whereas some teams like the one in Georgia focus on tests or like the team at Stanford (mentioned in my March 1, 2011 posting about their nanoLAB) focus on the device.

Not all of these new handheld diagnostic tools and tests are designed for disease identification. Argento (mentioned in my February 15, 2011 posting) is being used by UK Sport to assist their elite athletes prior to the 2012 Olympics.  Locally, i.e., in Vancouver, there’s a team at St. Paul’s Hospital, PROOF (mentioned in my Feb. 15, 2011 posting), working on a test that would eliminate the need for monthly biopsies for patients who have received kidney transplants.

Handheld diagnostic tool: nanoLAB

There’s a lot more action on the ‘handheld diagnostic equipment and abolish invasive testing’ front than I realized. (In my  Feb. 15, 2011 posting I highlighted the UK’s Argento [physical device and diagnostic tests for athletes] and PROOF [a Canadian group working 0n some new diagnostic tests for kidney patients and others].)

It turns out there’s another device, this one, to be found in the US, is called nanoLAB. From the Feb. 22, 2011 news item on Nanowerk,

In 2009, Stanford University faculty member Shan Wang and doctoral students Richard Gaster and Drew Hall demonstrated that they could use the same ultrasensitive magnetic sensors that form the basis of today’s compact, high-capacity disk drives in combination with mass-produced magnetic nanotags to detect small amounts of cancer-associated proteins (click here for earlier story).

Now, in a paper published in the journal Lab on a Chip (“nanoLAB: An ultraportable, handheld diagnostic laboratory for global health”), the three scientists show how they shrunk this technology to create a handheld disease-detection device that any individual should be able to use at home to detect illness and even monitor the effectiveness of anticancer therapy.

In my Feb. 15 posting I wondered about how the samples were actually conveyed to the device. I now know how nanoLab does it, presumably Argento uses a similar approach,

The device, which the researchers have named the nanoLAB, consists of a disposable “stick” that resembles a home pregnancy test, and a handheld magnetic reader that analyzes a patient’s urine, blood, or saliva for the presence of specific disease-associated proteins. In its current design, the nanoLAB can provide simultaneous yes-no answers for up to eight different disease-associated proteins. The handheld sensor unit costs less than $200 to produce, while the sticks capable of making eight measurements cost less than $3.50 each, and could drop to under $1 apiece with improvements already in the works. …

To conduct a test using the nanoLab, a person would add a drop of biological sample – urine or blood, for example – on the stick. They would then add the contents of two premeasured vials to the stick and then wait 15 minutes for results to appear in the form of a lit LED light on the sensor unit.

It’s not quite Star Trek yet but we’re getting there.