On average the protein yield from 1x106 cells of a cell line is 100-300 µg, dependent on the cell type.

To estimate the protein yield from one of your HMC3 100 mm plates you need to count the number of cells you will have per ml lysate.

Typical protein yields:

https://research.fredhutch.org/paulovich/en/typical-protein-yields.html

Thank You so much Ms. Sabine; I am grateful to you for your answer.

I have another question which method you are using to estimate the protein concentration? I use BCA kit to determine the protein concentration. Is it accurate?

We usually use the Bradford protein assay, both Bradford and BCA have advantages and disadvantages, but both are commonly used.

https://info.gbiosciences.com/blog/bca-or-bradford-protein-assay-choosing-between-the-two

https://citeqbiologics.com/support/bca-and-bradford-protein-assays/