Use of low-angle diamond knives leads to improved ultrastructural preservation of ultrathin sections

Low-angle diamond knives, one of them with an angle as low as 14.6 degrees, have been tested to measure compression induced during the sectioning of polystyrene latex spheres embedded in epoxy resins. Compression diminishes roughly proportional to the sectioning angle (sum of knife and clearance angles). The beneficial application of low-angle diamond knives in biology and material science is illustrated by sections through a muscle fiber (compression reduced by a factor of 3), sections through a collagen fiber (meridional resolution improved by a factor of 2) and sections through a copper grid bar (reduced curling). These low-angle diamond knives are as resistant as the classical knives having angles of 45 degrees and are routinely used by the author. Low-angle diamond knives with angles down to 35 degrees are now commercially available.