Staining properties of hyaline cartilage.

Despite numerous attempts to develop and evalute specsc methods for the histochemical demonstration of mucopolysaccharides, definitive information is not readily available. Thls is in spite of the notable contributions of Hale ('46); Steedman ('50); Gomori ('50); Kramer and Windrum ('54); Mowry ('56, '58); Spicer ('60); Belanger and Migicovsky ('61) and Goldstein ('62) to mention only a few. With few exceptions (Joel et al., '56; Warren and Spicer, '61) histochemical specificity has been determined by applying the method to a variety of tissue mucopolysaccharides. While this approach is appropriate for establishing differences between tissues, it usually provides little useful information about the method itself. This is not surprising since the chemical and physical properties of both the methods and mucopolysaccharides are obscure and the material stained may vary from tissue to tissue. An alternative approach (Davies, '52; Braden, '55; Pal and Schubert, '61; Spicer and Jarrels, '61) has been to employ "spot" or test tube methods in which purified mucopolysaccharides are utilized as the test material. The most obvious objection to this type of analysis is the assumption that the test material and the material in situ will exhibit similar properties. The artificiality of such an in vitro system renders such data open to question unless confirmed by other methods. The more useful approach to an understanding of histochemical procedures is the direct approach, i.e., the demonstration of tissue components by the application of the method to the material in situ. In order to do this it is necessary that (1) the material to be examined is preserved and (2) that it is preserved in as unaltered a condition as possible. Therefore fixation should be a primary consideration when methods are to be evaluated since consistent results cannot be obtained if the tissue components are inadequately preserved. Cetyl pyridinium chloride-formalin has been demonstrated to provide excellent preservation of acid mucopolysaccharide (Williams and Jackson, '56; Conklin, '63). Utilizing this fixative, the acid mucopolysaccharides of hyaline cartilage have been examined by histochemical methods. The excellent preservation of cartilage ground substance has in turn afforded a means of evaluating the specificity of the methods, the results of which are reported here.