Humans are visual animals. As the old adage goes: "Seeing is believing." So it is perhaps not surprising that much of the analytical instrumentation we have developed over the last century or so are based on light, whether refracted, reflected, absorbed or emitted. But in our game of analytical peek-a-boo (or is it peak-a-boo), we run the risk of putting on blinders and we may accidentally suffer from the adage corollary: "If we can't see it, it isn't there."
Perhaps as a way of filling in the holes or providing a second opinion, I have seen a growing body of acoustics-based instrumentation and applications. At last week's meeting of the Society for Biomolecular Sciences in Seattle, I sat down with Dr. Matthew Cooper, CSO of Akubio—more about them shortly. Cooper put the challenge of spectroscopy versus acoustics rather succinctly, I thought.
"Imagine you have a glass of beer [never a bad way to start a story], a glass of milk, and a glass of water. Spectroscopically, they are all very distinct, but acoustically, they are almost identical."
It was his way of saying that unlike many spectroscopic techniques, acoustics allows you to find the message despite the medium—at least in Akubio's case. The company has developed a molecular interaction detection device that looks like an SPR instrument, responds like an SPR instrument, but it definitely doesn't sound like an SPR instrument. Where other companies use an evanescent wave, Akubio uses the interaction of sound with a crystal to detect binding.
But one example does not a trend make.
Companies like Labcyte and EDC Biosystems are using sound to dispense ultralow but ultra-accurate volumes, eliminating many of the artifacts caused by pipetting errors or sample viscosities. And as I learned in my conversations with Georgia Tech's Dr. Mark Prausnitz (see October 2006 Drug Discovery News) and Bob Wilcox of EKOS, scientists are well on their way to using ultrasound as a very specific drug delivery mechanism, following in the heels (in some measure) of photodynamic therapy.
And as we've reported a few times this year, scientists have also effectively transferred the technology used to take baby's first photo to the preclinical setting, where companies like VisualSonics are using ultrasound to monitor the biological impacts of drug candidates in a variety of model organisms.
Sound still has a long way to go before it catches up to light as an analytical vehicle—it travels much more slowly, you know—but it is beginning to look like the only stumbling blocks are in the imaginations of the end-users.
Now, one question: If a biomacromolecule falls on a microfluidic chip and there is no one there to quantify it, is it really data?