New Monitoring Technique Provides Information About Life of Bacteria in Microdroplets
Updated: September 01, 2017 06:29AM UTC
by Institute of Physical Chemistry of the Polish Academy of Sciences
Date: Thursday, February 23, 2017
In the future, it will be possible to carry out tests of new drugs on bacteria much more efficiently using microfluidic devices, since each of the hundreds and thousands of droplets moving through the microchannels can act as separate incubators. So far, however, there has been no quick or accurate method of assessing the oxygen conditions in individual microdroplets. This key obstacle has been overcome at the Institute of Physical Chemistry of the Polish Academy of Sciences.
Not in rows of large industrial tanks, nor on shelves laden with test tubes and beakers. The future of chemistry and biology is barely visible to the eye: it's hundreds and thousands of microdroplets, whizzing through thin tubules of microfluidic devices. The race is on to find technologies that will make it possible to carry out controlled chemical and biological experiments in microdroplets. At the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw a method of remote, yet rapid and accurate assessment of oxygen consumption by micro-organisms living in individual microdroplets has been demonstrated for the first time.
The bioreactors of the future are water droplets with culture medium suspended in a carrier liquid with which they are immiscible (usually this is oil). In the channel of the microfluidic device each droplet is longer than it is wide and it almost completely fills its lumen; sizes matched in this manner ensure that the drops do not swop places in the channel and throughout the duration of the experiment they can be identified without any problems. At the same time, there has to be a thin layer of oil maintained continuously between each microdroplet and the wall of the channel. Without this, the bacteria would be in direct contact with the walls of the channel so they would be able to settle on them and move from drop to drop. Unfortunately, when the microdroplet is stationary, with time it pushes out the oil separating it from the walls, laying it open to contamination. For this reason the drops must be kept in constant motion - even for weeks.