Comparisons of microscopic pattern of neoplastic and non-neoplastic cells are of daily practical importance in the diagnosis of tumors and the management of cancer patients. Comparisons of chemical pattern are still largely in the field of research1 but are an essential step in furthering our understanding of neoplasia.2 For some years we3 have been applying new cell techniques developed by histochemists and cytophysicists to the study of human cancer.
One technique of considerable potential is the "pH signature."4,5 Proteins differ according to the nature and number of their constituent amino acids and conjugated substances.6 Proteins are amphoteric. They contain at the same time both basic and acidic groups, which, by their dissociation, give rise to positive and negative charges on the protein molecule. The ability of proteins to take up acid or basic dye according to the pH of the solution is an expression of
FORAKER AG. "pH Signature" of Skin CarcinomaAn Application of the "pH Signature" Technique to Sections of Skin of Basal- and Squamous-Cell Carcinoma. Arch Dermatol. 1961;83(3):392–401. doi:10.1001/archderm.1961.01580090042004