30 new research papers using CoolLED Illumination Systems were published from April to June this year. The applications span FRET, FISH, optogenetic stimulation and calcium imaging – as well as everyday fluorescence microscopy. You can browse these via our Technical Resource page, but here are a few we picked at random from the list:
In this paper, researchers seek to understand how the synaptic circuits in the brain become organised during development. They labelled two pools of progenitors in utero, marked by their differential expression of the Tɑ1 gene. Electrophysiology and anatomical analysis found that the neuronal types were a mix from both progenitor pools. Moreover, optogenetic circuit mapping using the CoolLED pE-300 Series for optogenetic stimulation, found that local inhibitory connections were also not dependent on the progenitor type. However, the same method found that the progenitor pool does determine the type of input from long-range synaptic circuits.
TTL triggering of LED illumination is highly beneficial for optogenetics. Available with both the pE-300white and pE-300ultra, fast and stable TTL triggering here allowed the researchers to apply highly controlled light pulses at ~1 mW and a duration of 2-3 ms.
van Heusden, F., et al. (2021). Diversity in striatal synaptic circuits arises from distinct embryonic progenitor pools in the ventral telencephalon. Cell reports, 35(4), 109041. https://doi.org/10.1016/j.celrep.2021.109041
As the threat of antimicrobial resistance grows, analysing the bacterial cell wall growth could yield clues about potential new drug targets. These researchers looked into cell wall growth by tracking fluorescently labelled bacterial flagellar motor complexes during E. coli growth and division, using time-lapse microscopy.
The pE-4000 Illumination System is ideal for time-lapse applications, where researchers can choose from 256 wavelength combinations across four channels to choose the optimum and most stable fluorophores. The simplicity of irradiance control also makes it easy to optimise the LED microscope lighting brightness to minimise photobleaching and allow extended analysis.
The pattern of growth revealed in this study (explained in detail in the full paper) could also be described by a mathematical model, and in addition to understanding this biological process in more detail, it would be interesting if one day a similar model could be used to test interference in cell wall growth by different chemical compounds.
Sun, Y. J., et al., (2021). Probing bacterial cell wall growth by tracing wall-anchored protein complexes. Nature communications, 12(1), 2160. https://doi.org/10.1038/s41467-021-22483-8
This research potentially has huge significance for drug development, with G protein-coupled receptors being important therapeutic targets. For all their significance, how the structure of the G proteins they associate with determines selectivity has, up until now, been unclear. This study is a great example of fast, efficient LED illumination for FRET. The researchers used two CoolLED pE-100 single-band LED Illumination Systems (440 nm and 500 nm) for CFP/YFP FRET in order to analyse molecular interactions and identify the protein regions involved in selective binding.
Jelinek, V., Mösslein, N., & Bünemann, M. (2021). Structures in G proteins important for subtype selective receptor binding and subsequent activation. Communications biology, 4(1), 635. https://doi.org/10.1038/s42003-021-02143-9