. Electron microscopy; proceedings of the Stockholm Conference, September, 1956. Electron microscopy. 302 M. W. ANDREWS AND J. SIKORSKI ever, the cortical cells isolated from untreated keratin by mild digestion in trypsin (3) appeared to be little affected by the prolonged action of ultrasonic vibra- tions (25 Kc/s and 15 Watt/cm-, actual output) in water or various swelling agents: the separated fragments showed very little internal structure (6). It was thus advisable to increase the time of treat- ment in trypsin to obtain better retting effects. The experiments were carried out with non-me
. Electron microscopy; proceedings of the Stockholm Conference, September, 1956. Electron microscopy. 302 M. W. ANDREWS AND J. SIKORSKI ever, the cortical cells isolated from untreated keratin by mild digestion in trypsin (3) appeared to be little affected by the prolonged action of ultrasonic vibra- tions (25 Kc/s and 15 Watt/cm-, actual output) in water or various swelling agents: the separated fragments showed very little internal structure (6). It was thus advisable to increase the time of treat- ment in trypsin to obtain better retting effects. The experiments were carried out with non-medullated root-ends of Australian merino and Lincoln wool fibres. These were cleaned by extraction in petroleum ether at room temperature for about a week, followed by Soxhiet extraction first in benzene and then in ethyl alcohol for 24 hours. The fibres were washed in repeated changes of distilled water to remove water-soluble impurities and then dried at room temperature. Fibres were then treated in a mixture, containing equal proportions of ;o w/v aqueous solution of trypsin and a buffer solution of pH , at 40 C, using a wool to solu- tion ratio of 1 :100. After three months both samples of wool retained their fibrous form, but on pressing gently between a microscope slide and a cover slip, they yielded cortical and cuticular cells; the latter were separated using Woods' technique (15). The purified cortical cells were kept (in a stoppered flask) in distilled water to which a drop of toluol had been added to prevent bacterial growth. Small samples of cortical cells were suspended in dis- tilled water, or lithium bromide solutions', in a cell of an ultrasonic apparatus (5) and were irradiated for periods up to 12 hours. The cortical cells isolated from Australian merino wool and irradiated by ultrasonic vibrations in water suspensions, appeared to break into large aggregates of the parallel macrofibrils, in agreement with the view that a macrofibrillar type of struc
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