Oil with RI of water for use with Olympus water objective

Dear all,

I have a 60X water immersion Olympus objective that I’d like to use for prolonged imaging. Thus, water is not an option for the immersion media, as it will evaporate over the course of the experiment. Olympus does not sell any oil with the RI of water (in contrast, Zeiss does for its W objectives), so I was wondering if anyone had experience with this.


  1. Are there particular water-RI oils that you know are (or aren’t) compatible with Olympus objectives?
  2. Are there particular water-RI oils that have lower fluorescence, convenient viscosity, and/or low dispersion, and would recommend?

The obvious options are Cargille and the Zeiss oil, any of which I would verify are compatible with Olympus before using on the objective. I was hoping the collective knowledge on the list would narrow my options down to a few good candidates.

Thanks in advance.


I use Zeiss Immersol W on an Olympus water immersion objective (bottom objective on a lattice) for months without changing it. Granted, it’s not a high NA lens, and we’re not asking much of the image quality there (and it’s a real pain to get to it to replace the media). I think many other people have also used Immersol across objective brands. So, i would certainly keep that on your list of options (but, as you said, do check with olympus just to be safe).

Thanks for the suggestion Talley.
I’ve asked Olympus whether they consider the Zeiss Immersol W to be safe on their objectives.
I’ll update when I get their answer.

I think Cargille also sells an oil with RI 1.33. I can’t seem to find it on the mobile-optimised site, but the home page mentions it. Might be worth checking the non-mobile site.

For medium time frames (5-8hrs w stage to heater) we have had good luck with GenTeal, an aqueous gel for eye dryness.


Thanks for those suggestions Wendy.

We have two types of Cargille oils with RI 1.33 at room temp and at 37C.

Our 20x WI objective has a very large working distance, and the oils are not viscous enough to allow contact with the sample.

I’ll echo Wendy’s statements regarding GenTeal.


Thanks for the information.
Luckily this is for a 60X W, with a much shorter working distance than your 20X, so contact should not be an issue.
With respect to the GenTeal, any problems with impurities that cause autofluorescence or reduce quality?

I haven’t done a hard core test–went with the assumption that if it’s intended to go in a human’s eye it’s probably pretty clean. Certainly nothing completely egregious. We were using it with 40X and 25X WI w 120-500um WD.

I think it costs ~$5 at your local drug store so it’s low risk to test!


Definitely Genteal eye gel. We’ve used is a lot on our $30K multiphoton 25X 1.05 WD2mm, and its awesome. We have a stock pile of Genteal as is was in short supply, but I think they’ve worked that out.


We use dye-free ultrasound gel on my facility. I have compared PSF with water and the ultrasound gel without seeing any difference.


James, I heard about the ultrasound gel as another substitute for water immersion long working distance objectives? any experience with that or Genteal is quite good to not even bother with the ultrasound gel?

Hi -

Genteal has been absolutely fabulous. I have also heard of ultrasound gel, you can buy it for a lot less money than Genteal, but the volume of our use is such that we’ve been ok continuing to use the Genteal. I haven’t compared them in any way.


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Thank you James that helps.

@claire @Freglis
Hi -
Could you comment on the evaporation of Genteal and ultrasound gels? Would they be suitable for >24hr imaging sessions? We moved to using silicone oil objective lenses as we ran into throughput issues with Immersol W in multi-xy timelapse movies and 72hr cell-fate analysis was impossible.


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Hi TEFK - I only saw this now. Di you need an immersion objective? I’ve done a lot of high NA air lens 72h and much more timelapse and cell fate analysis experiments. Regarding the Genteal, I don’t know how long its good for, only used out to 6 h in live animal with multiphoton microscopy. Good luck.

Hi James,

We required use of an immersion objective to resolve small 3D fluorescent-labeled structures and prevent any photo-toxicity (cell fate analysis) in our assays. As both GenTeal and ultrasound gels are water-based (i check ingredient lists), they will likely evaporate in stage-top incubators. Thanks for taking the time to comment.