Introduction

Elastica-Van Gieson kit is used for staining elastin, connective tissue and collagen. Elastic fibers consist of elastin polymers and elastic microfibrils that make up a 3D network in an extracellular matrix inside connective tissue (skin, elastic cartilage, vascular walls, lung tissue and in vocal cords). Unlike standard histology stains, Weigert Van Gieson reagent (known as a resorcin-fuchsin reagent) displays selective differentiation of tissue samples, even in the early phase of the disease. When using the Elastica-Van Gieson kit, the sections are first treated with Resorcine Fuchsin reagent. The positively charged hydrophobic resorcin-fuchsin dye is present in large amounts and it is deposited owing to electropolarity to acid, negatively charged shells of elastic fibers. After differentiation in diluted alcohol or rinsing in tap water, the nuclei are stained with acid-fast Weigert hematoxylin. The last phase of staining is staining with Fuchsin Acid Van Gieson reagent that contains two dyes (acid fuchsin, picric acid) that simultaneously stain different tissue structures. Acid fuchsin stains collagen fibers intensive red while picric acid stains muscle fibers, erythrocytes and glial fibers yellow. Sections are optimally stained in a short period of time by using a rapid staining method.