Division of Radiooncology, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany
Tissue sections have to adhere firmly to glass slides in all histological procedures. Adhesion is usually due to the close contact between flat surfaces. However, tissue sections are not really flat and slides are rarely perfectly clean. Moreover, histological techniques will often change the forces which enable firm contact between section and glass slide. In order to prevent loss of tissue sections during further treatment, adhesives such as starch paste, egg white, gelatin or bovine serum albumin (BSA) or chrome alum gelatin have been proposed. Yet, many of those adhesives are impracticable or unsatisfactory in immunohistology. The treatment of glass slides with L-polylysine was a breakthrough with respect to improved adhesiveness. With the introduction of positively charged glass surfaces by chemical reaction of slides with 3-aminopropyltriethoxysilane (APES), however, a most versatile method was found with the advantage that due to the method of covalent bonding positive charges are not washed away.