Hello
New to c elegans and research and very confused.
Would like to expose c elegans to glucose of varying concentrations and observe effects of it (fairly basic experiment…)
How do I expose the c elegans to glucose? Do I add it to the plates before the OP 50? Any protocols would help. I am planning on exposing it for 3 days, is that sufficient?
Should I expose it to glucose at the adult stage and also larval stage? I am already planning on doing ( young) adult stage.
We’ve done three methods: Adding glucose solution to the agar after it has been autoclaved (or reheated) and before pouring the plates, soaking glucose solution into dry plates before adding OP50, and suspending worms in an M9/glucose solution for 6-12 hours prior to the assay. The first method is what we use for the bulk of our experiments now, as it works well for introducing both soluble and insoluble reagents. But if you’re only working with glucose and other soluble reagents, the second and third method are both valid. The major thing you need to avoid is adding glucose prior to autoclaving your media, as it can degrade or react with peptone.
Both methods of introducing glucose to the plates produced strong phenotypes in adults when the worms were introduced as L1s; the second method seems to be prone to contamination, but this can be solved by filtering your glucose solution. Under room temperature growing conditions, glucose did not affect growth rate or premature death rate, even at 300 mM. I imagine they could tolerate even higher concentrations, but we were getting diminishing returns at this concentration in our assay (which already had an incredibly strong phenotype!) so we didn’t bother.
The suspension method produced equally strong phenotypes, but we occasionally saw that the directions of these phenotypes were different than those of the plate-raised worms; I’m guessing it’s because the plate-raised worms had more time to adapt to hyperglycemia.
I don’t have experience exposing the worms to glucose after reaching adulthood, as our assay focusses on first day adults. You’ll probably get a phenotype, but it may be a different phenotype than what you would have gotten if you’d raised them from L1s on the glucose.