What stain gives amyloid a red color against a clear background?

The Krajian's Amyloid stain is specifically designed to highlight amyloid deposits in tissues. This stain utilizes a specific dye that binds to the amyloid protein, resulting in a distinctive red color, which stands out against a clear or pale background when viewed under a microscope. This coloration is critical for pathologists to identify the presence of amyloid, which is associated with various diseases, including amyloidosis.

The other staining techniques mentioned are not primarily used for identifying amyloid. For instance, Masson’s trichrome stain is more commonly employed to distinguish muscle, collagen, and fibrin in tissues rather than highlighting amyloid deposits. Van Gieson’s stain is typically utilized for demonstrating collagen fibers in tissue samples, and Mallory’s stain is mainly used to visualize connective tissue and certain proteins, including keratin, but not specifically for amyloid. Therefore, the specificity and effectiveness of Krajian's Amyloid stain in providing the characteristic red coloration for amyloid deposits make it the correct choice for this question.