New Imaging Technique Allows Scientists to Watch Dozens of Molecules at Once

Nanotech

Scientists at Duke University developed a new imaging technique that allows them to look at the inside cells and watch molecules in action at once / Photo by: fw_gadget via Wikimedia Commons

 

Scientists at Duke University have developed a new imaging technique that allows them to take a peek inside cells and watch dozens of various molecules in action at once.

In the new method, observing cells and molecules are done by labeling them with short strands of light-up DNA that blink as they follow their own unique rhythm, Science Daily reports.

"The idea is everything has its own heartbeat," said Shalin Shah, the study's first author. Shah added that their team dubs these time signals as "temporal barcodes."

According to Science Daily, these barcodes could be used to spot and distinguish a number of things at a molecular scale when they are attached to cells and are observed for enough time. Some of the things that can be distinguished with temporal barcodes are certain proteins hidden among an abundance of other proteins that a human needs in order to function properly and grow.

It works by using the fleeting interactions among two complementary DNA strands as they bump into one another in the solution. One of the strands is connected to a molecule of interest for the study, while the other is free-floating and carries a fluorescent dye that lights when the two strands are paired up. The dye only goes back to dark when the strands are separated.

When viewed through a microscope, the pairing and coming apart produce a distinct flashing that serves as a fingerprint when decoded.

Traditional methods label molecules with the use of various color dyes. Some approach would use one color but varying DNA sequences and imaging stems, washing them off from one target before they move on to the next.

But the Duke University team believes they can do better.

"Our goal is to develop an economical and simple yet powerful method," Shah said. "The temporal intensity signals emitted are distinct and can act as a fingerprint."

Their approach raises the number of different signals that can be detected with just on dye color. Instead of relying on multiple DNA sequences, the Duke team maintains the sequence of the free-floating strand the same and adjust other things like the length or number of repeating sequences on the strand attached to the molecule being studied.

This kind of approach allows the strand to produce flashes with various frequencies, durations, and brightness.