Analyzing Cell-ECM Interactions in Adult Mammary Gland by Transplantation of Embryonic Mammary Tissue from Knockout Mice - Methods in Molecular Biology: Extracellular Matrix Protocols - page 332

Fig. 1. Location and morphology of murine mammary glands. (A) Location of adult
mammary glands and nipples; (B) Embryonic nipples of glands #2 and #3 in situ
(E17.5). Arrows indicate the pale circular nipples on the skin; (C) Whole mount of
embryonic rudiment (E17.5) stained with haematoxylin; (D) Wax section of rudiment
in (C) stained with haematoxylin and eosin.

3. Once located, remembering that the mammary rudiment extends just a short dis-

tance into the skin from the nipple ( Fig. 1C,D ), the skin should be gently lifted
using fine forceps and the nipple and gland cut away using watchmakers scissors
( see Note 7 ).

4. If the gland is to be used for transplantation, immediately it should be kept in

serum-free medium on ice. If not, it should be immediately frozen ( see Subhead-
ing 3.1.4. ).

5. On the first few attempts, to confirm that the mammary gland has been correctly

isolated, whole mounts can be used to stain the mammary rudiment ( Fig. 1C ). To
do this, the isolated gland should be gently spread, skin side down, on a glass
slide, allowed to dry to the slide for 30 s, and placed in Telly's fixative. The
subsequent procedure is exactly the same as for whole mount of adult mammary
glands ( see Subheading 3.3.2. ), although because the tissue is much smaller, the
time in each solution may be reduced.