when does the nuclear membrane dissolve

The nuclear membrane dissolves during late prophase / prometaphase of mitosis, just before chromosomes line up in the middle of the cell.

Key moment in the cell cycle

• In mitosis, the nuclear membrane stays intact through early prophase while chromosomes start to condense.

• As the cell enters late prophase (often called prometaphase), the nuclear envelope breaks down so spindle fibers can attach to chromosomes.

What “dissolve” really means

• The membrane does not literally melt; it disassembles into vesicles, the nuclear pores fall apart, and the supporting lamina breaks down due to phosphorylation of lamins.

• Once fragmented, there is no distinct nucleus, allowing the cell’s machinery to move and separate the duplicated chromosomes.

What happens afterward

• After chromosomes are pulled apart in anaphase, a new nuclear membrane reforms around each set of chromosomes in telophase.

• This re-formation restores two separate nuclei, each with its own envelope, preparing the cell to finish division in cytokinesis.

TL;DR: The answer to “when does the nuclear membrane dissolve” is: during late prophase / prometaphase of mitosis, as the nuclear envelope breaks down so spindle fibers can access the chromosomes.

Information gathered from public forums or data available on the internet and portrayed here.