Liver slice culture allows many “feeding trials” on the same individual, providing much better control over biological variation than live feeding trials. Here’s how: Cut out a small block of liver and superglue it to a plastic cylinder. Encase it in agar and mount it in a vibratome, a slicing machine. Each slice goes into its own lab dish, to be fed for example vegetable oil or marine oils.
Video credit: Tom Harvey
And here’s what you can see in the microscope after five days on different “diets”:
Image credt: Jacob Torgersen
The images show stained neutral lipids in three slices from the same fish, cultured on substrate containing no oil (some lipids from day 0 remain), vegetable oil (characteristically large drops of fat), and marine oil (characteristic small droplets of fat). Slices were stained for nonpolar fatty acids; images are 50 μm across. Omics analyses of gene expression and meta¬bolic activity are currently being investigated. Omics data from multiple in vitro diets will be extremely helpful for example in building mathematical models of salmon fatty acid metabolism.