Liquid NGM

I would like to know there is an article comparing worms lifespan in liquid Ngm and S basal. Could someone help?

Comparing S-medium vs. just S-basal for lifespan?

I personally don’t know of any studies nor can I imagine the worms being happy long term in the latter…

I’m not sure about comparing these 2 buffers but several papers look at lifespan in liquid.

The paper titled: Caenorhabditis-in-Drop Array for Monitoring C. elegans Quiescent Behavior from the Raizen lab looks at lifespan in liquid/oil drops.

Also studies with drugs like the paper titled: “An antidepressant that extends lifespan in adult Caenorhabditis elegans” are also performed in liquid. Several others if you take the time to do some crossreferencing.

[left]hi, i don’t know exactly what you are looking for or which exact media you mean when you say ''liquid NGM". i assume S-basal. if you are looking for really long term, multi-generational media, i’d say you are limited with S-basal, etc. it will keep them alive, but there is NO nutrition in them (unless you are adding bacteria)

There have been axenic medias developed for C. elegans which work.

here is a reference that might assist you though that might give recipes and conditions.

Curr Protoc Toxicol. 2007 Feb;Chapter 1:Unit1.9. doi: 10.1002/0471140856.tx0109s31.
The nematode C. elegans as an animal model to explore toxicology in vivo: solid and axenic growth culture conditions and compound exposure parameters.
Nass R1, Hamza I.[/left]

I assume the reference to liquid NGM made by the original poster meant just that:

http://cshprotocols.cshlp.org/content/2014/3/pdb.rec081299.full?text_only=true

http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html#d0e214

http://www.nature.com/protocolexchange/protocols/56#/reagents

etc. etc.

As far as the comparison between liquid NGM and S-basal, I assume again that the original poster was referring to OP50 suspensions in S-complete (or complete S-basal as it is also known)?

one example of which is: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3733581/

With the caveats outlined in this useful overview:

http://www.sciencedirect.com/science/article/pii/S0014579309007558

there’s lots to explore.

Given that the OP50 are just as tasty in S complete as they are in NGM media (which could both be changed regularly), the issue is more about how additional components present in the NGM but not in the S-complete might affect the lifespan assay.

However, everyone (and their mums) seems to be doing lifespan assays and there is a plethora of approaches, tweaks and lore. Well documented experiments and controls are the key.

Steve

There is, of course, the liquid media used by
NASA for the worms in space projects. It
is a complete chemical diet, bacteria free.

The generation time is about five+ days at 20 C.

Dave

Thank you Steveh.
I am talking about survival assays comparing liquid NGM (NGM whithout agar) or S basal. I saw few articles that use liquid NGM with HB101,
…my doubt is related to why not use OP50 in liquid NGM? Bway I am doing this now…let’s see what happens!

Athough there are differences in metabolic products, there appears to be little effect on lifespan between HB101 and OP50 on solid NGM:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0007545

you get stronger growth with HB101, but if you titre your feeding then OP50 could also be used and has been used (see the above refernce)

Liquid culture isn’t really a strong suit of mine, but as I recall for liquid culture you grow the food separately and often kill it (by freezing and perhaps desiccation) before adding it to the media. A lot of the argument in favor of OP50 is that it grows on plates to a relatively thin lawn that minimally interferes with your ability to spot young larvae, while HB101 (for example) grows more thickly on plates (these are of course not the only consequences of using the two strains on plates, but they were the initial arguments). This argument at least rather falls apart when you are growing the bacteria separately and adding a fixed concentration to your liquid culture.