How can I keep worms in culture medium for more than 10 days?

Originally posted on WormAtlas by “Caenorhabditis elegans”, May 20, 2004

How can keep the worm in culture medium more than 10 days? Thank you!

Caenorhabditis elegans

Originally posted on WormAtlas by “Anonymous”, May 20, 2004

Is your goal to raise individual animals to older ages? When growing animals on plates, it is often helpful to gently transfer the older adults to fresh plates every few days. This not only gives them fresh food, but more important, will move them away from their younger progeny, who are more active, and may take resources away from the old animals.
Transfering old animals to new seeded plats with a pick is much easier than trying to remove progeny from the original plate.

Originally posted on WormAtlas by “Caenorhabditis elegans”, May 24, 2004

Why, if we want to keep worms for long, should we replace them to clean agar? Is the bacteria or their waste reducing their life span? I read a paper that said because of their intestinal bacteria, but my boss says there are very many reasons that cause the nematodes to not have an integrated life span if left in only one agar plate. However, we don’t do this kind of research.

Caenorhabdtis elegans

Originally posted on WormAtlas by “hall”, May 24, 2004

Moving the old animals to a fresh culture plate may indeed move it away from adverse products; but I do not know. The main reasons we move them is more for convenience and to optimize their nutritional status, since any culture plate typically changes into a “starvation” environment after 3-6 days. Many older animals die prematurely when they go into a “bag of worms” phenotype - their last few progeny hatch inside the uterus and begin to eat the mother animal from the inside. Older animals that have not “bagged” may still be cannibalized by swarming progeny from the outside as the culture plate runs out of other food sources. Old animals often become immobile, puffy and flaccid, and may be too weak to escape predation. This body weakness also makes them difficult to transfer safely by pick after about 12-15 days; they can be damaged just by physical contact. So it is safer to move them at day 10, when they have just halted production of fertilized oocytes.

None of this answers your question about the buildup of toxic products. Perhaps you can design an alternate method to investigate this.

David Hall