There were no reports on the morphological study of the human mammary gland.
Although the mammary gland in the rodent have been studied by light and electron microscopy. In this study, 141 samples of human milk were investigated by macroscopic, light microscopy and electron microscopic examinations in order to assess the quality of individual human milks.
A drop of human milk (20μl) was dropped with in 20 μl oil-red solution or 1% osmium solution, and examined by macroscopic and light microscopy. Each lipid droplet was stained red or black respectively. Lipid droplets were varied in density according to individual human milk. About 30% of samples examined by us were small in number. Lipid droplets were spherical in shape and their sizes tended to become bigger with growth. Foremilk with yellow color was 1.5-3.0 μm, transitional milk with light yellow color was 2.0-6.0 μm, and mature milk with white color was 2.0-6.0 μm.
The secretion consisted of lipid droplets was enveloped by the cell membrane, and rarely contained casein granules and rough endoplasmic reticulum, no fusion of lipid droplets were found.
It was concluded that the oil-red osmium staining method was simple and very useful for assessment of human milk.