The negative stain is particularly useful for determining cell size and arrangement. It can also be used to stain cells that are too delicate to be heat-fixed. We use nigrosin as our negative stain. Nigrosin is an acidic stain.
To 2040 A.D. Until late 2006, global temperatures were more than a degree Fahrenheit warmer when compared to the 20th Century average. From August of 2007 through February of 2008, the Earthâs mean temperature dropped to near the 20th Century average of 57 degrees.
The world's highest recorded surface temperature is 56.7 Â°C (134 Â°F) measured at Greenland Ranch in Death Valley, California, USA on July 10, 1913. The mean temperature in Dallol, Ethiopia is 34.4 Â°C (94 Â°F), the highest annual average temperature on earth. 1  Hottest Cities in the World.  Hottest Countries in February.