High-speed centrifuges that operate at 90,000 to 100,000 rpm are known as:

High-speed centrifuges that operate at speeds of 90,000 to 100,000 rpm are categorized as ultracentrifuges. These specialized centrifuges are designed to create extremely high centrifugal forces, which can separate biological molecules, macromolecules, or organelles based on their sizes and densities with great precision.

Ultracentrifuges are often utilized in molecular biology and biochemistry laboratories for tasks like sedimentation of viruses, purification of subcellular components, and analysis of nucleic acids or proteins. The high rotational speeds facilitate the sedimentation of particles that would otherwise remain suspended in solution much longer in standard centrifuges.

In contrast, other types of centrifuges serve different purposes or operate at lower speeds. Horizontal-head centrifuges and fixed angle-head centrifuges are generally employed for various routine laboratory separations but do not reach the high speeds characteristic of ultracentrifuges. Cytocentrifuges are specifically designed for concentrating cells onto a microscope slide for cytological studies and also do not operate at the speeds found in ultracentrifuges.