Reprints 1-50

Date:
1950-1963
Reference:
PP/CRI/M/1/1
Catalogue details

Licence: In copyright

Credit: Reprints 1-50. Source: Wellcome Collection.

    1/455
    Reprinted from Experimental Cell Research, Vol. 1 No. 1, 1950. THE PHYSICAL PROPERTIES OF CYTOPLASM A STUDY BY MEANS OF THE MAGNETIC PARTICLE METHOD Part I. Experimental F. H. C. CRICK and A. F. W. HUGHES Strangeways Research Laboratory, Cambridge, England Received October 5, 1949 A. INTRODUCTION This paper has two aims: first to describe our experimental work on the physical properties of the cytoplasm of chick fibroblasts in tissue culture, with a short discussion of its implications and secondly to present such de tails of the magnetic particle method as to enable other workers to use it. A second part will be devoted to the theory underlying these methods. B. TECHNIQUE In this section we shall describe in outline the methods we have used, leaving the details to later sections. Our basic technique, which was suggested to us by Dr. Honor B. Fell, is to allow cells growing in tissue culture to phagocytose small magnetic particles, and then to move these particles in the cytoplasm by means of external magnetic fields. It is possible to make certain limited deductions about the physical properties of the cytoplasm from the character and mag nitude of the movements. The magnetic materials we have used have been in a finely divided form. The material is added to the culture medium of the original expiant. The cultures are then allowed to grow for three days after which they are sub- cultivated into the normal medium. In the subsequent outgrowth, cells containing phagocytosed particles can be observed under high power. The expiants were usually from the frontal bone of an 11 or 12 day chick embryo. In applying the magnetic field to the particles within the cells we have experimented with three types of movement, which can be described as
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