Its very easy dear, you just need to pour methanol on that overlay medium (1-2 ml) and leave it for few minutes. Methanol start polymerizing agarose, then from needle/syringe you can easily take out agarose overlay medium..

Thanks Priyanka for the solution. I have doubt regarding these:-

1. Can I follow the same with methylcellulose overlay?

2. Methanol should be at room temperature or -20degrees while adding on to the agarose overlay.

Methylcellulose overlay must be viscous, you can easily take out through pipettes or by suction. I have used agarose overlay medium and used methanol for its removal. Methanol should be at room temperature

We actually switched from methyl cellulose to Avicell since the cell monolayer stays completely intact using 1% Avicell in DMEM for plaque assays for dengue virus, yellow fever virus and VEEV. The overlay is way less solid but still prevents virus spread uncontrolled through the culture

We also have found Avicel works most easily in many of our assays. However, methylcellulose seems better for mouse L929 cells. We have not yet figured it out but no monolayer remains after Avicel usage on the L929. In both cases, the overlay is poured off, the monolayer rinsed once with PBS, then fixed in 2% formaldehyde (in PBS)

Hi Joydeep, I use methylcellulose from Sigma Cat No - M0512. For virus titration (plaque assay), final conc is 1% in the overlay medium.

You do not need to remove the methycellolose since it is too viscous to aspirate out and it is easy to wash out after staining. You can simply wash it off with water.