Imaging System for Monitoring Calcium Flux in Parabolic Flight
Elisa Barney Smith
This year’s Boise State Microgravity University team is building a system which will excite osteocyte mono-cultures and osteocyte-osteoblast co-cultures with 350nm light and then image the emission for free calcium or bound calcium at 485nm and 405nm, respectively. In order to image these wavelengths, the system built needed enough resolution to image a 5mm diameter well of a microtiter 96 well plate and to differentiate between wells in close proximity since all 96 wells fit into a 3x5 inch area. This made imaging and image post processing difficult due to bleed over from one well to the next. Another complexity of the system is that it needed to image these wells during a 30s period of micro or hyper gravity, requiring the exposure time and time between captures to be small. The imager itself needed to be sensitive enough that it can capture the specific wavelengths without introducing unnecessary noise even though the signal will not have significant luminosity. The team used two different mono-chrome imagers using C-mount band-pass filters in order to isolate both 405nm and 485nm emissions simultaneously with one imager per wavelength. After capturing the images, post-processing will be performed utilizing digital image filtering and manipulation methods to determine how much luminosity from each well was caused by unbound or bound dye, allowing a quantification of free calcium. The team expects that, as with last year’s cells, there will be a definite correlation between the gravitational stress on the cells to the amount of free calcium in each well.