Analytical Cytology: Methods for Studying Cellular Form and Function

By Robert C. Mellors | Go to book overview
Save to active project

CHAPTER 1 Cytophotometric Analysis in the Visible Spectrum



Department of Zoölogy, Columbia University


Of all the techniques of analytical cytology with the compound microscope, perhaps quantitative absorption analysis in the visible spectrum is destined to become most widely used. First and foremost, this tool offers the possibility of expressing in objective values the differences in intensity of natural color or of the stains and tests which have been developed by histochemists and cytochemists for localization of substances in cells (Chap. 2). Visual comparisons are of very limited use in resolving any question where variations in both concentration and cell volume are involved, but where the chemical and physical conditions are favorable for absorption analysis, it is not a difficult procedure to obtain data from which the relative amounts of absorbing substance can be computed over a wide range of concentration. Swift (111), for example, was thus able to estimate desoxyribose nucleic acid in spherical nuclei, where the highest concentration was over twenty times that of the lowest. This possibility of objective measurement of intensity should make a microspectrophotometer as essential a piece of equipment in any histological, pathological, or cytological laboratory as the spectrophotometer is in a modern biochemical laboratory.

Second, and of nearly equal importance, is the role of visible microspectrophotometry as an adjunct to biochemical and physiological studies which seek to localize chemical components and functions within the cell. Very often such studies involve an estimate of the number of cells in the analytical sample and a computation therefrom of the amount of the components in the average cell. This is an unjustifiable procedure and of dubious value unless it is supported by cytological studies of the variation within the group. For example, it was thus computed by biochemists that the "average nucleus" from a number of different tissues of an animal contained the same amount of desoxy


Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Cite this page

Cited page

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited page

Bookmark this page
Analytical Cytology: Methods for Studying Cellular Form and Function


Text size Smaller Larger
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen
/ 32

matching results for page

Cited passage

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?