Mouse and human milk membrane enclosed structures vary in morphology and size distribution.

a) Brightfield images of human and mouse milk immediately after expression show cells and milk fat globules, collectively referred to as membrane enclosed structures. Scale bars: 10 μm. b) Human and mouse milk membrane enclosed structure populations differ in size and granularity as measured by front and side scatter on flow cytometry. c) The size distribution of membrane enclosed structures varies for human and mouse milk samples. This graph was generated from 5–6 images per sample.