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 combined average temperature over global land and ocean surfaces for DecemberâFebruary was the eighth highest on record for this period, at 0.57Â°C (1.03Â°F) above the 20 th century average of 12.1Â°C (53.8Â°F).