. Contributions from the Botanical Laboratory, vol. 11. Botany; Botany. ^1 i» ^)^\ >. fj -V A* â¢-â â¦Â» > AMINES IN CYTOLOGICAL FIXING FLUIDS' By Conway Zibkle (Department of Botany and Morris Arboretum, University of Pennsylvania) With Plates VI and VII Received for publication August 14, 1933 Following the discovery of the importance of chromosomes in the study of heredity, cytological research has emphasized the fixation of cells in such a manner as to bring out the greatest possible nuclear detail. Acid fluids have proven to be the best preservatives of chromatin, nucleoli and spin
. Contributions from the Botanical Laboratory, vol. 11. Botany; Botany. ^1 i» ^)^\ >. fj -V A* â¢-â â¦Â» > AMINES IN CYTOLOGICAL FIXING FLUIDS' By Conway Zibkle (Department of Botany and Morris Arboretum, University of Pennsylvania) With Plates VI and VII Received for publication August 14, 1933 Following the discovery of the importance of chromosomes in the study of heredity, cytological research has emphasized the fixation of cells in such a manner as to bring out the greatest possible nuclear detail. Acid fluids have proven to be the best preservatives of chromatin, nucleoli and spindle fibers, and consequently the fixatives which have been developed for the investigation of nuclei are either mixtures of acids, acids and salts, or more complicated solutions whose fixing properties are determined by their acid components. As a result, cytological investigation has been concerned more with the fixing properties of anions than of cations. In fact, there is but one cation in the usual fluids, which has any real influence upon the image, i. e. hydrogen. While a number of the fixing mixtures contain salts of heavy metals, such as mercury, gold, silver, platinum, osmium and copper, they fix at such a hydrogen ion concentration that the characteristic images of the metallic ions are obscured by a typical acid fixation. Differences in the specific properties of the several cations can be recognized only on the basic side of pH â These have been recorded in a number of cases with bichromate and acetate fixation (Zirkle 8, 9). When chromic acid is brought to pH â with sodium, potassium or ammonium hydroxide the resulting bichromate gives the basic fixation image. In Zea Mays the nucleolus is fixed as a solid heavily staining sphere in intimate contact with the surrounding fixed nuclear lymph. All chromatin and spindle fibers are dissolved. In dividing cells the nuclear lymph which permeates the division figure is coagulated and forms a regular
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Keywords: ., bookcentury1900, bookpublisherphiladelphiasn, booksubjectbotany
