Collagen fibres: collagen is the most widespread and most abundant structural protein

• In H & E staining → Red or Pink
• Picrosirius Red → Bright Red
• Van Giesan’s method → Red
• Mallory’s → Blue
• Masson’s trichrome stain → Green when light green is used

Reticular fibres: these can be stained by certain silver impregnation stain and PAS.

• In They form a delicate, flexible network around capillaries, muscle fibres, hepatocytes, etc. They are an integral part of the basement membrane.

Elastic fibers: These fibers are present in organs those requires elasticity in addition to tensile strength. They can be stretched to 2 ½ times then original length. They can be seen in external ear, vocal cords, trachea, lungs, ligamentum nuchae, skin and arteries.