Light micrograph of cholesterol crystals (also known as clefts), which form needle-like (white) lines in tissue. Here the crystals are mixed with blood, which forms the red to light purple-pink coloured areas. The presence of cholesterol crystals in human tissue is usually due to long standing inflammation or injury in the affected tissues. Haematoxylin and eosin stained tissue section. Magnification: x400 when printed at 10cm wide.