Protocol

Long-Term Frozen Storage of Choanoflagellate Cultures

¹Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94704, USA
²Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94704, USA
³Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
⁴Department of Biology, University of York, York YO10 5YW, United Kingdom
⁵School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom

⁶Corresponding author (b.s.c.leadbeater{at}bham.ac.uk)

This article is also available in Emerging Model Organisms: A Laboratory Manual, Vol. 1. CSHL Press, Cold Spring Harbor, NY, USA, 2009.

INTRODUCTION

Choanoflagellates are heterotrophic nanoflagellates: small, colorless protozoa that are present in marine and freshwater environments as well as in hydrated soils. Because they are the closest living relatives of the metazoa, the study of their cell biology and genomes promises to provide new insights into metazoan ancestry and origins. Choanoflagellates can be stored under stable conditions by freezing them with liquid nitrogen, as described here. To prevent cross-contamination among vials stored in the liquid phase of a liquid nitrogen freezer, the use of CryoFlex tubing to fully seal the vials is encouraged.