Journal Article

Cytochemistry and C-values: The Less-well-known World of Nuclear DNA Amounts

J. Greilhuber

in Annals of Botany

Published on behalf of The Annals of Botany Company

Volume 101, issue 6, pages 791-804
Published in print April 2008 | ISSN: 0305-7364
Published online October 2007 | e-ISSN: 1095-8290 | DOI:
Cytochemistry and C-values: The Less-well-known World of Nuclear DNA Amounts

More Like This

Show all results sharing these subjects:

  • Ecology and Conservation
  • Evolutionary Biology
  • Plant Sciences and Forestry


Show Summary Details



In the plant sciences there are two widely applied technologies for measuring nuclear DNA content: Feulgen absorbance cytophotometry and flow cytometry (FCM). While FCM is, with good reasons, increasingly popular among plant scientists, absorbance-cytophotometric techniques lose ground. This results in a narrowing of the methodological repertoire, which is neither desirable nor beneficial. Both approaches have their advantages, but static cytophotometry seems to pose more instrumental difficulties and material-based problems than FCM, so that Feulgen-based data in the literature are often less reliable than one would expect.


The purpose of this article is to present a selective overview of the field of nuclear DNA content measurement, and C-values in particular, with a focus on the technical difficulties imposed by the characteristics of the biological material and with some comments on the photometrical aspects of the work. For over 20 years it has been known that plant polyphenols cause problems in Feulgen DNA cytophotometry, since they act as major staining inhibitors leading to unreliable results. However, little information is available about the chemical classes of plant metabolites capable of DNA staining interference and the mechanisms of their inhibition. Plant slimes are another source of concern.


In FCM research to uncover the effects of secondary metabolites on measurement results has begun only recently. In particular, the analysis of intraspecific genome size variation demands a stringent methodology which accounts for inhibitors. FCM tests for inhibitory effects of endogenous metabolites should become obligatory. The use of dry seeds for harvesting embryo and endosperm nuclei for FCM and Feulgen densitometry may often provide a means of circumventing staining inhibitors. The importance of internal standardization is highlighted. Our goal is a better understanding of phytochemical/cytochemical interactions in plant DNA photometry for the benefit of an ever-growing list of plant genome sizes.

Keywords: C-values; Feulgen densitometry; Drosera rotundifolia; flow cytometry; genome size; Pisum sativum; polyphenols; staining inhibitors; standardization; tannins

Journal Article.  9536 words.  Illustrated.

Subjects: Ecology and Conservation ; Evolutionary Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.