Media Releases

Digital microfluidics opening the way for revolution in blood sampling

August 30, 2011

Professor Aaron Wheeler’s lab-on-a-chip automates dried blood spot analysis in a system that is “fast, robust, precise and compatible with automation”

TORONTO, ON – The days of the blood sam­ple rou­tine – arm out, tie tube, make a fist, find a vein, and tap in – may soon be over, thanks to a new analy­sis method devel­oped at U of T by Insti­tute of Bio­ma­te­ri­als and Bio­med­ical Engi­neer­ing (IBBME) core pro­fes­sor Aaron Wheel­er in which only a pin­prick of blood nec­es­sary.

Tra­di­tion­al meth­ods of blood sam­pling requires intra­venous extrac­tion of sev­er­al mil­li­l­itres of blood. A phle­botomist then sep­a­rates serum, which is frozen for trans­port or stor­age, and lat­er thawed and ana­lyzed. A rel­a­tive­ly new alter­na­tive to the tra­di­tion­al method uses blood sam­ples stored as dried blood spots (DBSs). The DBS method requires only a pin­prick to extract a few microlitres of blood, which is blot­ted onto fil­ter paper, where the sam­ple, it has been found, remains sta­ble. While DBSs have been gain­ing increas­ing pop­u­lar­i­ty for the ease of sam­pling and stor­age for some time, they are still not a stan­dard lab­o­ra­to­ry tech­nique, and the process for using them remained labo­ri­ous – until now.

In a study pub­lished in Lab on a Chip last week, Wheel­er and col­leagues demon­strat­ed the proof-of-prin­ci­ple that dig­i­tal microflu­idics could be used to auto­mate the process of dried blood spot analy­sis in the case of test­ing for spe­cif­ic genet­ic dis­eases at New­born Screen­ing Ontario (NSO) in Ottawa. This paper is the result of a col­lab­o­ra­tion between Wheel­er and NSO rsearchers.

NSO reg­u­lar­ly screens every baby born in Ontario for genet­ic dis­eases – some 140 000 babies a year – and col­lects DBS sam­ples via heel­prick. Each DBS must be man­u­al­ly col­lect­ed. Tech­ni­cians must pre­pare the sam­ple for test­ing, put it into a cen­trifu­gal tube, pipette sol­vent onto the sam­ple, extract the nec­es­sary mate­r­i­al by cen­trifuge, and then use robot­ics to con­duct the chem­i­cal analy­sis.

Wheeler’s dig­i­tal microflu­idic plat­form auto­mates this process. Droplets are manip­u­lat­ed onto the sam­ple using elec­tri­cal sig­nals, and the mate­r­i­al need­ed for analy­sis is extract­ed – all on a “lab-on-a-chip” with lit­tle man­u­al inter­ven­tion. Wheel­er cre­at­ed the pro­to­type for this process in the Bahen Clean­room, a facil­i­ty of the Emerg­ing Com­mu­ni­ca­tions Tech­nol­o­gy Insti­tute at U of T.

Wheeler’s study quan­ti­fied par­tic­u­lar amino acids that are mark­ers of three meta­bol­ic dis­or­ders:

phenylke­tonuria, homo­cystin­uria, and tyrosine­mia. His next steps will be to eval­u­ate the rest of the 28 dis­eases that NSO screens for.

Wheeler’s inno­va­tion is indica­tive of the inno­v­a­tive tools for bio­med­ical engi­neer­ing that IBBME researchers cre­ate. “The appli­ca­tions for this process go far beyond new­born screen­ing,” Wheel­er stat­ed. “Phar­ma­ceu­ti­cal com­pa­nies are mov­ing towards dried blood spot analy­sis, but they’re still lack­ing the tools to make wide­spread use fea­si­ble. We’ve demon­strat­ed that dig­i­tal microflu­idics could be that tool. Our sys­tem is fast, robust, pre­cise, and com­pat­i­ble with automa­tion.”

While it might be a while before the days of the dread­ed blood sam­ple nee­dle are behind us, Wheeler’s dig­i­tal microflu­idics method is the next step in mov­ing to a DBS-based sam­pling sys­tem, says Pranesh Chakraborty, Direc­tor of NSO. “This approach could save con­sid­er­able costs as a result of the low­er vol­umes of reagent required,” he affirmed. “An auto­mat­ed sys­tem based on this approach would also process sam­ples faster, with high­er accu­ra­cy, less risk of errors, all while free­ing up time for tech­nol­o­gists to per­form oth­er work.” Charaborty’s team pro­vid­ed the screen­ing and med­ical per­spec­tive in this research.

A patent has been filed, and Wheel­er is cur­rent­ly explor­ing com­mer­cial­iza­tion options.

Aaron Wheel­er holds the Cana­da Research Chair in Bio­an­a­lyt­i­cal Chem­istry. He holds appoint­ments in Chem­istry, IBBME, and the Bant­i­ng and Best Depart­ment of Med­ical Research.

The Insti­tute of Bio­ma­te­ri­als & Bio­med­ical Engi­neer­ing (IBBME) is an inter­dis­ci­pli­nary orga­ni­za­tion based in three Fac­ul­ties at the Uni­ver­si­ty of Toron­to: Applied Sci­ence and Engi­neer­ing, Den­tistry and Med­i­cine. The Insti­tute pur­sues research in four areas: neur­al, sen­so­ry sys­tems and reha­bil­i­ta­tion engi­neer­ing; bio­ma­te­ri­als, tis­sue engi­neer­ing and regen­er­a­tive med­i­cine; mol­e­c­u­lar imag­ing and bio­med­ical nan­otech­nol­o­gy; med­ical devices and clin­i­cal tech­nolo­gies.




For more infor­ma­tion, please con­tact:

Sachiko Muraka­mi
Com­mu­ni­ca­tions Offi­cer
The Insti­tute of Bio­ma­te­ri­als and Bio­med­ical Engi­neer­ing (IBBME)
Uni­ver­si­ty of Toron­to