A section of an ovary is isolated from a Xenopus laevis frog and put into a storage solution (OR-2). Oocytes are isolated from this partial ovary. Many types of recordings are done with oocytes that have their follicle removed. This is usually done enzymatically, using collagenase. For our experiments, we will usually be using oocytes with the follicle intact. These can be dissected directly out of the ovary as see below.
When viewed through the dissecting microscope, the ovary will look something like the picture on the left.
When the ovary is removed form the frog, the oocytes are held tightly together with blood vessels and connective tissue.
Single cells are dissected out of the group with long, heavy gauge needles.
Choose a health looking stage 5 or 6 cell to work with.
Using the needles, pull the selected cell away from the clump of cells.
The cells are somewhat fragile, so you can't grab them directly. Try to dissect out the cell by pulling and tearing at the connective tissue.
Once you have a cell dissected away from the bunch, push it into a clear, identifiable section of the Petri dish.
You should isolate 4-5 oocytes before starting an experiment because some oocytes won't be suitable for use once you impale them.
Back to Main Oocyte page