The methylene blue is unable to penetrate viable cells leaving them unstained.

Scientists suspect that the globular body binds to and penetrates cells, causing most of the misery.

Our Scimitar missile had to penetrate the radar array and solar cells.

No daylight penetrates concrete cells where the earth has been bulldozed up to the roof line.

Gentamicin can sometimes penetrate eukaryotic cells and kill the internalized bacteria.

On entering the blood stream the merozoites penetrate other endothelial cells.

Merozoites will penetrate other cells and create more merozoites for one to several rounds.

However, in order to be biologically viable they must (1) easily penetrate cells, and (2) not be toxic to the cell.

Because an effective anti-cancer drug must penetrate cells, it will probably have to be a small molecule, researchers say.

The question of how viruses penetrate cells is central to understanding viral diseases.