Cells are the basic unit of life, and their density is a fundamental property that can influence a wide range of biological processes, including metabolism, transport, and signaling. However, accurately measuring the density of cells has been challenging due to their small size and complex composition.

Now, researchers at the University of California, Berkeley, have developed a new method to measure the density of cells using a technique called buoyant mass density centrifugation. This method involves suspending cells in a density gradient and then centrifuging them until they reach their equilibrium position. The density of the cells can then be determined by measuring the density of the surrounding fluid at their equilibrium position.

The researchers used their new method to measure the density of a variety of cell types, including red blood cells, white blood cells, and cancer cells. They found that the density of cells varied depending on the cell type, with red blood cells having the highest density and cancer cells having the lowest density.

The researchers also found that the density of cells could be affected by a number of factors, including the cell's size, shape, and composition. For example, cells that are larger or have a more irregular shape tend to be less dense than cells that are smaller or more spherical. Cells that contain more lipids are also less dense than cells that contain more proteins or carbohydrates.

The new method developed by the researchers provides a valuable tool for measuring the density of cells. This information can help researchers to better understand the structure and function of cells, and it may also lead to the development of new diagnostic tools and treatments for diseases that affect cell density.