Microtools

Abstract

Microbiologists utilize a large diversity of microtools which are carried and guided in the field of the microscope by means of suitable micromanipulators. Such microtools, also called assistants or microinstruments, are of different types, shapes, and functions to satisfy varied requirements in different fields of study of cells and tissues. In the investigation of living cells, in single cell surgery for instance, the operator can remove the nucleus or a part of it or other cell constituents from individual cells and replace them by others. To perform these tasks the operator may use microneedles, microknives, micropipets, microforceps, and a variety of other tools. Microdissection needles may be made so fine as to puncture red blood corpuscles and to tear up leucocytes. Minute quantities of fluid can be injected into a cell by means of fine micropipets connected to a suitable injection apparatus in order to study the effect of these injections on the nucleus or the protoplasm. For such operations micropipets may be made with fine orifices a few microns to less than half a micron in diameter. Micropipets may also be used in single cell isolation to deliver or to collect tiny droplets in which the bacterial cell is contained. It is also possible to measure differences in the potentials over very short distances, for example at the poles of a cell, by inserting microelectrodes. A variety of glass assistants used by microbiologists are shown in Fig. 92, and a still wider variety is illustrated in Figs. 105 to 110 in connection with the use of the de Fonbrune microforge in preparing microtools.