Houston, we have a solution

Researchers in Houston, Texas, have developed a solution for optimising photoluminescent probes for studying DNA, using time-resolved spectroscopy and some careful calculations.

Rice University scientists found that using time-resolved spectroscopy to optimise photoluminescent probes for studying DNA can provide results twice as good as the standard procedure of fluorescence spectroscopy for specific sequences.

The method has been common in the lab of Angel Martí, an assistant professor of chemistry and bioengineering, who has spent several years working with fluorescence spectroscopy. However, the technique has yet to be published, which is why he took it upon himself to document proof of the concept.

He said: "I thought there must be some publication out there that would describe the tools we use, but there weren't any.

"So we've had to write them."

Using time-resolved spectroscopy to optimise results from photoluminescent probes essential to the study of microscopic structures such as cells, proteins and DNA doubled the efficiency of a hairpin-shaped probe. The probe is often referred to as a molecular beacon in finding a specific DNA sequence by maximising the amount of signal pulled from the background noise.

The problem with photoluminescent probes is that even in an experiment lasting a fraction of a second, a spectrometer can return too much information and obscure the data researchers actually want.

Time-resolved spectroscopy provides part of the answer, according to Martí, who described the process as being like taking a film instead of a snapshot. He said: "We create a kind of movie that allows us to see a specific moment in the process where photoluminescence is occurring.
Then we can filter out the shadows that obscure the measurement or spectra we're looking for." 

By editing the 'movie' in real time, they chop off the front and back to narrow the data set to a range that might last only 80 nano seconds.  

Posted by Neil Clark