Congo Red Highman kit
Three-reagent kit for staining amyloids, characteristic for use of alkaline solution as differentiation medium in order to avoid undesirable non-specific colouration of cellular substances. Amyloid deposits display green colouration under polarised light.
Congo Red Puchtler kit
Three-reagent kit for staining amyloids, characteristic by its high ionic strength and pH enhancing the specificity of Congo Red dye binding to amyloid clusters. This method developed by Puchtler remains the gold standard for amyloids in tissue sections. Amyloid clusters have the property of double refraction that enables green colouration under polarised light.