GRIN lens holder recommendation for 0.6mm NAc implant (RWD 68201/68213 vs Kopf 1770)

[Choi Gi-Hwan]

Hello everyone,

We're setting up a mouse Miniscope experiment targeting the NAc
(nucleus accumbens) in our lab. We're planning to use an Inscopix
0.6mm diameter x 7.3mm length GRIN lens — if a different size is
better suited for NAc, please let me know.

For the lens holder, since the lens diameter is small, I think a
commercial holder would work better than making one from cut
pipette tips. Several papers (e.g., Zhao et al. 2025, PLoS One)
use the Kopf Model 1770 for 0.5-0.6mm lenses, but there's no
Kopf distributor in Korea, so we're considering RWD's 68201
(clamping range 0.3-1.5mm) or 68213 (clamping range 0.4-4.0mm)
as alternatives.

A few questions:
1. Has anyone used RWD 68201 or 68213 specifically for holding a
   0.6mm GRIN lens? Any issues with grip or stability?
2. Between 68201 and 68213, which would you recommend for this
   diameter?
3. Is there anything we should watch out for when substituting
   Kopf 1770 with an RWD equivalent?

Thanks in advance for any insight!

[Nat Kinsky]

Hi Choi,

I have never used an electrode holder to implant a GRIN lens so I don't have advice on that front.

However, I have used a 3d printed version from Omid Yaghmazadeh that I adjusted to accommodate the exact lens you are using for rat prefrontal cortex imaging and it worked well. That discussion is here: https://groups.google.com/g/miniscope/c/lLyPUdEEhzg/m/MVpwtGH7AQAJ

If you decide to go that route be sure to either use my design and manually file down the tip of the holder to give clearance for cementing the lens to the skull after implant, or adjust Omid's V3 model .stl file from a 1mm hole to a 0.6mm hole.

Nat