Journal of Applied Phycology

, Volume 22, Issue 6, pp 725–731 | Cite as

Refining cryptophyte identification: matching cell fixation methods to FISH hybridisation of cryptomonads

  • Linda K. Medlin
  • Sabine Strieben


The Division Cryptophyta, Class Cryptophyceae, contains ecologically important microalgae that are found in all aquatic habitats. The identification of the Cryptophyta is challenged by a need to examine species in the scanning electron microscope or transmission electron microscope to visualise features needed to identify its species. Molecular verification is becoming increasingly important for this group because of its polymorphic haploid and diploid cells of the same species with different morphologies. Thus, for routine monitoring programmes, this group is not usually identified beyond the level of class and that is done only if the samples are routinely examined with a fluorescent microscope or with flow cytometry, and the cryptophytes are counted based on the natural orange fluorescent of their phycobilin pigments. In order to use rRNA probes, the cells must be fixed for permeabilisation of the cell membrane for probe penetration. Here, we present a test of routine fixation methods to determine the fixation that is most compatible for use in fluorescent in situ hybridisation methods with fluorescent microscopy and flow cytometer to facilitate cryptomonad identification.


Cryptophytes Fixation methods Flow cytometry FISH hybridisation 


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Laboratoire AragoObservatoire Océanologique de Banyuls-sur-merBanyuls-sur-MerFrance
  2. 2.Alfred Wegener Institute for Polar and Marine ResearchBremerhavenGermany

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