Personally I would use PBS and get the final dilution to where you will not damage the worms.

In terms of which PBS to use I would always suggest you get the more concentrated because you can dilute it as a stock solution but you can basically never do that with the diluted stocks. 

I don't inject Ascaris with buffers so I'm not sure what concentration to use.

Dear Zakka,

In this article: Darawshe S, Tsafadyah Y, Daniel E. Quaternary structure of erythrocruorin from the nematode Ascaris suum. 2000;242(1987):689-694.

The authors clean the adults with destilled water and then dry them in the air. I always clean the worms with sterile water.

I do not know why do you want to dilute the body fluid of the worm. You could break the pseudocoelomocytes with a sonicator. Anyway, if you want to dilute it you should use PBS 1x.

Chehayeb JF, Robertson AP, Martin RJ, Geary TG. Proteomic analysis of adult Ascaris suum fluid compartments and secretory products. PLoS Negl Trop Dis. 2014;8:e2939.

To wash the Ascaris suum after isolating, PBS 1x would be better than Normal Saline (0.9% NaCl). I have been using PBS 1x for washing Haemonchus contortus isolated from sheep abomasum and found better results with it.

I suggest PBS1x

To

Mr. Reeves

Thank you for your kind answer. Actually I won't inject the worm, I'll dilute its body fluid in vitro.

To Mr. González-Fernández

Thank you for the answer and the reference included. It's very helpful. I'm going to use PBS for diluting the body fluid.

To Mr. Rakesh

Really? I actually don't have any idea that washing the worm with different reagent would give a different result. Thank you for sharing your experience.

To Mr. Flores-Abuxapqui

Thank you for your answer. I'm going to use PBS for my research then.

I actully donty  have any  idea  that washing the worm with different reagent would give a different result.Thank you for sharing  your experience