Abstract
This apparatus is designed for the purpose of dissecting living cells or injecting substances into them, and for isolating micro-organisms. Its advantage over that which Barber described in the Philippine Journal of Science in 1914 is its simplicity of construction, and the accuracy with which it can be manipulated.
The apparatus consists of two instruments, the micro-manipulator for producing movements in the microscopic field in any of three dimensions and, second, the micro-injection instrument for securing the necessary pressure to drive or suck substances through a micro-pipette. The method of making glass micro needles and pipettes is given in full in Barber's paper and in mine in the Biological Bulletin of 1918.
The micro-manipulator is small and compact and can be attached to the stage of any microscope. It consists of a system of rigid metal bars connected together with spring hinges. By turning certain screws the bars are forced apart. On reversing the screws the springs return the bars to their original positions. The instrument moves the tip of a needle or a pipette in three arcs at right angles to one another. The arcs are small enough so that, in the microscopic field, the needle moves practically in straight lines. The movements are fine and steady enough to be under perfect control when viewed under the highest power of the microscope. The instrument can be used singly for one needle only or with a companion when two needles, or a pipette and a needle, are to be used simultaneously.
In the micro-injection instrument mercury or an inert oil (Nujol) is used to procure the necessary pressure. The instrument consists of a thin-walled steel tube about six inches long and half an inch in diameter, one end of which is provided with a stopcock.
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