MICROSCOPY AND MANIPULATION OF CELLS IN ELASTIC CAPILLARIES

Microscopy in round glass capillaries does not give an acceptable image of the contents because of strong distortions. Square, and generally right-angle, capillaries provide a higher quality image, but no access to the cell. Capillaries of elastomers combine good optical quality with access to the cell, and a great variety of manipulation through the capillary and by the capillary. Three properties are most important for capillary cell manipulation: (1) extensibility or elongation limit of a capillary, reaching 7-8 times and more, with latex, polyurethane and silicone; (2) transparency, which is sufficiently high for transmitted light microscopy in thin layers of elastomers; and (3) hardness, low in elastic materials, permits puncturing the capillary wall to reach the cell. Capillaries, owing to their softness and flexibility, may be flattened easily to improve observation. Cell manipulations, then, are possible with extensible capillaries: (1) elongation of the cell into a thin strand 7-8 times longer than cell diameter, thus separating cell structures; (2) excision of cell parts; (3) precise microscopy of the nucleus and organelles not masked by the cytoplasm; (4) microinjection; and (5) stimulation of contraction and relaxation of the cell.