The staining kit LH: CALLEJA staining is used in food histology to differentiate and analyze specific structures in food samples. It allows overview staining of food products for qualitative analysis of components in terms of origin and condition.

The particular suitability of this staining kit is that it differentiates reprocessed tissue, as the staining properties of various components are permanently altered by heating. This allows fresh muscle tissue to be differentiated from heated muscle tissue, as well as elastic tissue from collagenous tissue, such as bone and cartilage.

The chemical components of the staining kit, nuclear red and picro indigo stock solution, interact specifically with tissue structures to impart different colors. In doing so, they stain cell nuclei reddish, muscle tissue light green to brownish or light green when heated, elastic connective tissue yellow, and collagenous tissue blue or light blue when heated.

CALLEJA staining works because of the binding affinities of the dyes to the respective tissue components. Through these chemical bonds, tissue structures are visualized and can be analyzed microscopically. This staining kit makes a significant contribution to food quality control.