Use of hematoxylin stain to enhance evaluation of heart malformations in the fetal rat

Fresh and formalin fixed visceral microdissection techniques are valuable t ools for studying cardiac teratology in the fetal rat, but are limited by t he difficulty experienced in visualizing the minute structures needing to b e evaluated. This paper describes a simple and quick staining technique use d to enhance the examination procedure. A hematoxylin-saline mixture applie d directly on endothelial-lined surfaces of the heart at different stages d uring microdissection greatly improved visualization of membrane-thin struc tures such as the pulmonary and aortic semilunar valves, right- and left-si de atrioventricular valves, and atrial and ventricular septa. Hematoxylin s taining of endocardial surfaces is a useful adjunct to the standard viscera l microdissection technique. (C) 1999 Wiley-Liss, Inc.