2 . M E T H O D S
45
vials containing clotted plasma in which the tissues are included.
Although this was probably the earliest tissue-culture method to be
attempted (Loeb, 1897; Loeband Fleisher, 1919) it did not prove to be
very satisfactory and has now been virtually abandoned. It was
mostly used in the early days of "organ culture" for studying the
histology of the central explants which were fixed and stained after
varying times in culture (Champy, 1914; Strangeways and Fell, 1926;
Carle ton, 1925). Observations of the living cultures were difficult,
conditions of oxygenation bad, and better methods are now available
for organ culture (see p. 70).
If a fluid medium is used, containing a suspension of cells, and a
coverslip or slide placed in such a stationary tube or bottle and inclined
at an angle towards the surface of the fluid, the cells settle on the
coverslip and may arrange themselves, according to types, at different
depths. Such cultures have been made from bone-marrow and blood
(Osgood and Krippaehne, 1955).
I I I .
C E L L C U L T U R E
A. C E L L I S O L A T I O N A N D P U R E STRAINS OF CELLS
1. Differential Survival
Many years ago, Baker (1933) described a method by which monocytes from fowl blood could be obtained in culture in a fluid medium of
serum alone and successfully grown on the glass surface at the bottom
of a flask. Small fragments of the "buffy coat" of blood, which had
been coagulated with tissue extract after centrifugation, were explanted
into a plasma coagulum. All types of leucocytes at first wandered out
rapidly into the medium and on to the glass. After several days,
however, most of these had died, except the monocytes. By stripping off
the clot, these cells could then be obtained in isolation on the glass
surface where, if now supplied with fresh serum every few days, they
could be kept alive, and, in the case of chick monocytes, multiplying
indefinitely or at least for very long periods.
Such cultures were among the first cell cultures as opposed to tissue
cultures to be made, though it is only fair to say that Jolly (1903) had
studied the division of newt leucocytes in hanging-drop preparations
thirty years previously.
Whenever cells can be obtained in suspension (see p. 49) in a fluid,
it may be desirable to separate out a particular class from which to
culture. This can sometimes be done by differential centrifugation in
solutions of sucrose or albumen of the appropriate density or by
45
vials containing clotted plasma in which the tissues are included.
Although this was probably the earliest tissue-culture method to be
attempted (Loeb, 1897; Loeband Fleisher, 1919) it did not prove to be
very satisfactory and has now been virtually abandoned. It was
mostly used in the early days of "organ culture" for studying the
histology of the central explants which were fixed and stained after
varying times in culture (Champy, 1914; Strangeways and Fell, 1926;
Carle ton, 1925). Observations of the living cultures were difficult,
conditions of oxygenation bad, and better methods are now available
for organ culture (see p. 70).
If a fluid medium is used, containing a suspension of cells, and a
coverslip or slide placed in such a stationary tube or bottle and inclined
at an angle towards the surface of the fluid, the cells settle on the
coverslip and may arrange themselves, according to types, at different
depths. Such cultures have been made from bone-marrow and blood
(Osgood and Krippaehne, 1955).
I I I .
C E L L C U L T U R E
A. C E L L I S O L A T I O N A N D P U R E STRAINS OF CELLS
1. Differential Survival
Many years ago, Baker (1933) described a method by which monocytes from fowl blood could be obtained in culture in a fluid medium of
serum alone and successfully grown on the glass surface at the bottom
of a flask. Small fragments of the "buffy coat" of blood, which had
been coagulated with tissue extract after centrifugation, were explanted
into a plasma coagulum. All types of leucocytes at first wandered out
rapidly into the medium and on to the glass. After several days,
however, most of these had died, except the monocytes. By stripping off
the clot, these cells could then be obtained in isolation on the glass
surface where, if now supplied with fresh serum every few days, they
could be kept alive, and, in the case of chick monocytes, multiplying
indefinitely or at least for very long periods.
Such cultures were among the first cell cultures as opposed to tissue
cultures to be made, though it is only fair to say that Jolly (1903) had
studied the division of newt leucocytes in hanging-drop preparations
thirty years previously.
Whenever cells can be obtained in suspension (see p. 49) in a fluid,
it may be desirable to separate out a particular class from which to
culture. This can sometimes be done by differential centrifugation in
solutions of sucrose or albumen of the appropriate density or by