Thermo Fisher GeneFrames are adhesive spacers widely used in bacterial cell biology to make small sealed agarose pads on microscope slides for time lapse microscopy. The GeneFrames protocol was developed by Jan-Willem Veening and is available on JoVE. They work well for obligate aerobic bacteria such as Bacillus subtilis because it is straightforward to cut large air spaces either side of a narrow agarose pad within these frames.

Unfortunately, Thermo discontinued these items in 2025. BioRad FrameSeals, which as far as I can tell are the identical product under a different brand name, are also discontinued.

Last Updated 11-06-2026 We found the following alternatives to this product. Based on pricing and initial tests, I recommend the iSpacers as the best replacement for GeneFrames.

  • iSpacers from SUNJinLab. After discussion with us and other labs, SunJinLab have how launched a substitute which specifically matches the dimensions of the old square GeneFrames for bacterial timelapse imaging with 25x25mm coverslips. Price is reasonable ($105 for 250 iSpacers). We already tested a different dimension iSpacer for time lapse imaging of Bacillus subtilis and observed good growth. Once we receive the new dimension iSpacers we will test them too. There are various other sizes of iSpacer dimensions available on their website - for anyone that requires a different size, note that we found the 0.3mm thickness to match the thickness of GeneFrames most closely. Thanks Ivan Volkov and George Churchman for first identify iSpacers as a possible substityte.

  • Grace Biolabs have recently released SecureSeal Frames, a GeneFrame compatible replacement product. My lab have tested the prototype version of these and they work fine for Bacillus subtilis time lapse microsopy. However, at $115 for 25, they are quite pricy at 4x the cost of the old GeneFrames.

  • There is probably a good DIY solution. The key step would be to identify a suitably non-toxic double sided adhesive sheet material. Hobbyist die cutters or makerspace laser cutters could be used to cut the sheet.

Author: Séamus Holden