Living diatom cells can be isolated from their surrounding assemblage of cells and in kept alive in cultures. Culture collections have staff that do the time-consuming work to maintain strains of diatoms over the long term. These collections provide a valuable source of living cells that can be purchased. Many also provide the solutions (media) for growing algae in culture. In addition, culture collections often accept unique strains from diverse geographic locations for inclusion in their libraries.

The University of Texas Algal Collection (UTEX) includes special collections of algae in the Freshwater Diatom Collection, Extreme Environment Collection, Snow Collection, and Salt Plains Collection.

The Algal Resources Collection (ARC) is focused on taxa that contribute to Harmful Algal Blooms (HABS).

Bigelow National Center for Marine Algae and Microbiota serves as a facility to receive, maintain, and distribute living cultures of marine and freshwater algae. They also provide technical expertise educational resources for culture isolation and curation.

Carolina Biological Supply is a commercial source for algal cultures.