Fluorescent dye uptake in C. gigas eggs

A preliminary experiment was conducted to determine the natural uptake of fluorescent dextran dye (Dextran, Fluorescein, 3000 MW, Anionic from ThermoFisher) in C. gigas eggs. Eggs were collected and held overnight in a refrigerator before the experiment. They were then placed in a solution containing dye for 20 minutes, washed several times in filtered seawater, and imaged. Below are light microscope images and fluorescent images using a FITC filter.

light fluorescent

As can be seen, no fluorescence is seen aside from a spot in what appears to be something other than an egg.

Previous unpublished research had indicated that small molecules may enter an egg at the same time as fertilization, which could be a method for introducing something such as a morpholino to alter gene expression. To this end, dye solution was added along with an appropriate concentration of activated sperm and allowed to incubate for 10 minutes. Eggs were then washed several time in seawater and eggs imaged, seen below.

light fluorescent

In this instance, multiple eggs in each frame are fluorescing, indicating that the dye has either become attached to the surface or entered the egg itself. This result is a promising first finding of the method for introducing desired molecules in eggs.

Written on July 5, 2022