Greatly increases light-gathering power with high-power objectives Formulated to give refractive index of 1.5150 ± 0.0002 for D line at 23°C (73°F) Nondrying, so index will not change when exposed to air Contains no polychlorinated biphenyl (PCB) compounds Conforms to ISO 8036/1 specifications Standard for all oil-immersion microscopy Type A oil has low viscosity and low fluorescence Type B is a high-viscosity oil used in biomedical microscopy Type NVH is a high-viscosity oil that meets requirements for horizontal, inverted and inclined instruments and projection equipment Type FF oil is virtually nonfluorescent Type DF is a very low-fluorescence oil for fluorescence microscopy with very high resolution