Professor Colin Brownlee, Marine Biological Association
Plymouth Director 2007-2017, Marine Biological Association Chair of Marine Biosciences, University of Southampton
Phytoplankton play a critical role in Earth’s carbon and nutrient cycles, and in the regulation of our climate, yet are relatively poorly understood. The Brownlee Group at the Marine Biological Association study various processes that occur in living phytoplankton ranging from interactions between large populations of organisms to processes within single cells. Conventional microscopes and objectives are incapable of studying large enough populations of cells with sufﬁcient resolution to discern sub-cellular details. The group therefore use the Mesolens system, a 4× objective with nearly 0.5NA, which can provide highly detailed images for a ﬁeld of view 5mm across. The Mesolens, developed by Brad Amos and Gail McConnell at the University of Strathclyde, uses precision-made lenses to minimize spherical and chromatic aberration across the huge ﬁeld of view.
The group are using calcium imaging to study dynamic behaviour in large populations of diatoms and coccolithophores expressing R-GECO, and need to preserve sub-cellular details and structures. A conventional CMOS camera wouldn’t have the ﬁeld of view and resolution to take advantage of the Mesolens, so a moving-array CCD was previously used – however this camera was incapable of the sensitivity and speed required for calcium imaging.
The Iris 15 [Scientific CMOS camera] gives us the field of view, resolution and sensitivity to use calcium imaging to study interactions between large populations of cells with single-cell resolution on our Mesolens microscope.