Fomblin

This page is meant to be a collection of notes on Fomblin with regard to the LCN's standard operating protocol for ex vivo samples.

Background: Fomblin is the name brand of a fluoropolymer produced by Solvay Specialty Polymers S.p.A. that has been used since 1998 (Huang, G. Y., et al., 1998) as an immersion solution to improve MR-imaging SNR in tissue samples. The fluoropolymer uniquely lack's any MR-signal but has magnetic susceptibility similar to that of tissue, which results in MR-images with high SNR & CNR between the Fomblin and any suspended tissue. Since the use of Fomblin in MR-imaging is still quite young, the impact of the solution on tissue properties is unknown. We are maintaining this wiki page to document the following 5 levels of ex vivo processing with Fomblin to record any personal and literature-based experiences with the solution.

5 levels of the ex vivo procedure where Fomblin can impact tissue:

1. Packing
2. Scanning
3. Post-Processing
4. Histology
5. Tissue storage

Packing

Scanning

History

We were initially using Fomblin LC08 from Solvay Solexis - Solvay Solexis stopped selling Fomblin LC08 a few years ago, so we transitioned to using Kurt J. Lesker products. - Initially we used Fomblin 06/6 from Kurt J. Lesker (for specs, see page 5 of the attached PDF). - However, the specific gravity of Fomblin 06/6 was slightly higher than that of LC08, and as a result it was more technically challenging to pack whole brains in this fluid within an air-tight plastic bag for ex vivo MRI. - We therefore transitioned to Galden HT200 (Galden is just a brand name of a Fomblin product) because of its lower specific gravity, which has made the brain packing process go more smoothly (for specs see page 2 of the attached PDF).

I don't believe that anyone in our lab has noticed any differences in the quality of the imaging data acquired with these three slightly different fomblin solutions. I am cc'ing Allison Stevens, the lab manager at the MGH Martinos Center's Lab for Computational Imaging, to make sure I am not missing any recent updates.

Post-Processing

Histology

Hyare et al., 2008

Hyare et al., 2008 found that storing tissue in Fomblin for 2 days prior to MRI had no effect on scan or histology results when compared to matched samples stored in 10% formol-saline.

Synopsis: Formalin-fixed mouse brain tissue placed in Fomblin for 2 days prior to T1, T2, DWI, and MTR scans @ 9.4T produced the same results as formalin-fixed controls placed in 10% formol-saline solution 2 days prior to scanning. Both were scanned in Fomblin. They compared ROI-based quantitative MR measures, anatomical & cellular histology, and immunohistochemical staining.

• Fluorinert has been used in a number of studies. A quick search came back with +5 exvivo studies since 2004 using Fluorinert as an in-scan solution - typically Flourinert FC-77, not FC-3283.

• 3M Fluorinert Electronic Liquids for Electronics: https://www.3m.com/3M/en_US/company-us/all-3m-products/~/All-3M-Products/Electronics/Chemicals/Chemicals/Fluorinert-Electronic-Liquids/?N=5002385+8709318+8710710+8711017+8736409+8745514+3294857497&rt=r3

• Studies using Flourinert: Noristani et al., 2015, Colon-Perez et al., 2015, Kovačević et al., 2004, etc..

Tissue Storage