The phrase "inside the cell" is correct and usable in written English.
For example, you could use it in a sentence such as: "The scientists were able to observe the changes inside the cell."
Once inside the cell, the RNA gets to work.
Instead, he was forgotten inside the cell for four days.
The principal images were placed inside the cell chamber.
"This opens the door to make machines that live inside the cell," Dr. Montemagno said.
It is the proteins that it encodes that actually do the work inside the cell.
Inside the cell it is damaged by the harmful byproducts of life-sustaining chemical reactions.
Inside the cell, mitochondria turn food and oxygen into adenosine triphosphate, which produces energy.
Inside the cell, the methanol combines with water to make carbon dioxide, hydrogen ions and electrons.
The factor has a groove that precisely fits its target protein inside the cell.
It sets off a chain of events inside the cell that leads to cell growth and division.
From inside the cell, all one can see through the perforated metal door is another white wall".
