In histology, the HPS stain, or hematoxylin phloxine saffron stain, is a way of marking tissues.
HPS is similar to H&E, the standard bearer in histology. However, it differentiates between the most common connective tissue (collagen is yellow) and muscle and cytoplasm are both pink, unlike an H&E stain, which stains connective tissue, muscle and cytoplasm all pink.
HPS stained sections are more expensive than H&E stained sections, primarily due to the cost of saffron.