The units kilogram, gram, milligram, microgram, and smaller are commonly used for measurement of mass. The protein is prepared in a lyophilized 1 microgram dose. Using available microgram quantities of einsteinium, femtogram quantities of mendelevium-256 may be produced. Life-cycle cadmium emissions from coal is 3.1 microgram/kWh, lignite 6.2, and natural gas 0.2 microgram/kWh. The toxin can cause death if more than 0.5 microgram is consumed. Current PV technologies lead to cadmium emissions of 0.3-0.9 microgram/kWh over the whole life-cycle. Polonium is available for about $100 per microgram. A typical self-luminous watch that uses radium paint contains around 1 microgram of radium. Drugs active in microgram range, most notably LSD, are commonly distributed on blotting paper. "Starseed launcher" was concept for launching microgram interstellar probes at up to 1/3 light speed. The amount isolated depends on the analytical method, but is generally less than one microgram.