|Equipment - Fluorescence dissecting scope|
|Leica MZ-12 dissecting microscope with epifluorescence
We use this microscope frequently. It is invaluable for selecting GFP-expressing seedlings for further analysis on the confocal. This is especially true when GFP expression is segregating. This microscope made possible our high-throughput cDNA::GFP screen by letting us detect GFP expressing T1 individuals out of a high background of untransformed and non-expressing transgenics.
There are genetic screens currently underway at Carnegie in which GFP expression is being used as an assay for gene expression patterns. This microscope allows rapid plus/minus screening of large numbers of individuals in these screens.
Several projects are making use of particle bombardment to transiently express genetic constructs. Particle bombardment has been useful for rapidly testing GFP fusion constructs, and to express constructs that might otherwise be lethal or deleterious in embryo and seed development. The fluorescence microscope allows us to rapidly detect expressing GFP expressing cells in Arabidopsis seedlings or in other tissue that has been bombarded. We are currently developing a project where GFP will be used as a cell transformation marker to identify cells that are have been transformed with putative dominant-negative alleles of Arabidopsis genes. This will allow us to ask how expression of these alleles may affect individual cell function in intact mature tissue.