Which configuration for dark field blood imaging? 0.6 nozzle and PETG possible?

Hello and thank you again, William,

i am only using PETG and ABS with my printer as i have problems with nozzle clogs when using PLA because of high humidity and temperatures where i live. A friend will bring me 1KG of carbon enhanced PETG next week so i can print parts which need to be stiff using this filament.

My biggest problem right now is sourcing the non printed parts. I did read up on lenses on this forum but i am still not sure which lense to buy.

This one has been confirmed to work but i am not sure which resolution i should buy:
https://www.aliexpress.com/item/32961348843.html

In the thread about this lense you say that the 100x would require oil immersion and recommend going for a 40x magnification lense. Is this correct? Example:

(Sorry, i am still reading up on microscopes and how openflexure works)