Most chromatography methods have an inert mobile phase that carries the analyte through a long stationary phase housed inside a column. The stationary phase is designed to separate the components of the analyte based on some defined characteristic, which causes some molecules to migrate through the stationary phase more slowly and others to pass through more quickly. Stationary phases exist which can divide analytes along the strength of their polarity, how well they bind to certain chemicals, their ionic charge, or their size. For example, in gel permeation chromatography, special inert beads are used as the stationary phase, and the mobile phase carries the analyte past those beads. Because of how the beads are designed, larger molecules will spend less time in the column as they move through the gaps in the beads. As a result, the largest molecule will leave the column first and the smallest last. The separated analyte components pass from the column through a flow cell, where unique technology is employed to detect the presence of the components in the mobile phase stream.