Mammary Gland Development in Mice

Female FVB virgin mice were harvested at exactly five, six, seven, and eight weeks of age. Total fat pad length was measured prior to dissection. Glands were harvested and fixed in 4% Paraformaldehyde for 3 hours and cleared in 50% Glycerol 50% PBS solution overnight. Both inguinal glands were stained with DAPI according to the protocol previously described [56 (link)]. Images were taken using a Leica MZ16F dissecting microscope equipped with a Leica DFC300 FX camera and analyzed with MetaMorph 7.1 (Molecular Devices Inc.). The total length of the fat pad and the distance from the nipple to the ductal front were measured using MetaMorph 7.1 (Molecular Devices Inc.). The true distance of ductal growth was calculated by multiplying the percent fat pad filled by the original length of the fat pad prior to harvest.