Calcium oxalate crystals in urinary sediment

Ingestion of Ethylene glycol (antifreeze) leads to acute renal failure. Oxalate is a product of the metabolism (breakdown) of ethylene glycol and is excreted by the kidneys. It can combine with calcium to form calcium oxalate monohydrate crystals which injure the renal tubules. The crystals are excreted in the urine, which can be reduced to protein components and analysed. This image uses polarized light to create a dark background against which the typical 'cigar shaped' calcium oxalate monohydrate crystals can be viewed. The variable blue, pink or yellow colours of the crystals are created depending on their orientation to the lambda compensation plate. Horizontal image width 215 micrometres