Protists and disease : vegetable protists: algae and fungi, including Chytridiineae, various Plassomyxinae, the causes of molluscum contagiosum, smallpox, syphilis, cancer, and hydrophobia together with the Mycetozoa and allied groups / by J. Jackson Clarke.

  • Clarke, J. Jackson (James Jackson), 1860-1940.
Date:
1922
Catalogue details

Licence: In copyright

Credit: Protists and disease : vegetable protists: algae and fungi, including Chytridiineae, various Plassomyxinae, the causes of molluscum contagiosum, smallpox, syphilis, cancer, and hydrophobia together with the Mycetozoa and allied groups / by J. Jackson Clarke. Source: Wellcome Collection.

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    As Wilson points out, there is no specific stain for chromatin. Similar staining' reactions do not necessarily mean chemical identity; both the nuclei and matrix of cartilage stain alike with methyl green. Staining reactions have their value and we should be able to make use of every technical resource ; at the same •y time we must not forget that a process which reveals one feature brilliantly will conceal others of equal importance; nor that technique is a means, not an end. Bodies suspected of being protists should invariably be first carefully examined unstained in conditions as nearly as possible like those in which they are discovered, and then in water. In this wav alone can we let them show by their own activities if they are living organisms. They should also be tested by attempting cultures in water as described below in Chapter VI. Intravital Staining.—Methylene blue, neutral red, and other dyes are used to stain living tissues and organisms. Their applicability is limited ; it is generally agreed that when a nucleus takes a stain it is dead. Neutral red stains granules, and it has the advantage of being a test of acid 01 alkaline reaction, becoming brighter red with the former, yellow with the latter. It is a basic dye, its name referring to its tint. Janus green (Hoechst) has been found to stain the mitochondria of living human lymphocytes; mitochondria, being soluble in alcohol, chloroform, and ether, are destroyed by the ordinary processes.