This staining technique is a metal impregnation technique used to demonstrate reticulin fibres providing contrast enabling even the finest of fibres to be seen. Reticulin fibres have poor affinity for silver solutions but treatment with potassium permanganate produces sensitised sites where silver can be deposited. This deposition of silver ions requires an optimum pH of 9.0. Post treatment with formaldehyde solution causes deposition of the silver ions as silver metal. Excess silver is removed by treatment with sodium thiosulphate.