Isolation of primary mammary cells
Ca2+ chelating solution	Store at 4 °C
EDTA	0.02% w/V
PBS
Collagen I coating solution
Acetic Acid 0.02N, pH 3,23
Rat Tail Collagen (coating)	1:50
Dispase solution	Store at 4 °C
Dispase	5 mg/ml
PBS
Dissociation Medium
DMEM:F12
Hyaluronidase Stock Solution	400 U/mL
Pen/Strep	1x
Stock solution collagenase I	600 U/mL
Haemolytic Solution	Store at 4 °C
NH4Cl Solution	1 parts
TrisBase 20.6 g/L	9 parts
adjust pH to 7.2
HBSS/PS	Store at 4 °C
HBSS
Pen/Strep	2x
Hyaluronidase Stock Solution	Filter 0.2 µm, store at 4 °C
Hyaluronidase from bovine testes (powder)	2,000 U/mL
Sodium phosphate Buffer 1M pH7.3
NH4Cl Solution	Store at T. amb.
H2O
NH4Cl	7.1 g/L
adjust pH to 7.65
Sorting Solution	Filter 0.2 µm, store at 4 °C
BSA	0.1%
EDTA	1 mM
HEPES pH 7	25 mM
PBS
Wash Medium #1
DMEM/F12
Pen/Strep	1x
Wash Medium #2
DMEM/F12
FBS	5%
Pen/Strep	1x
Mammary 2D culture medium
DMEM/F12
FBS	2%
heparin	4 mg/mL
L-Glutamine	1x
murine bFGF	10 ng/mL
murine EGF	10 ng/mL
Pen/Strep	1x
Induction and Passaging of yMaSCs
Mammary Colony Medium
DMEM:F12
FBS	5%
heparin	4 µg/mL
L-Glutamine	1x
Matrigel (add immediately before seeding)	5%
murine bFGF	20 ng/mL
murine EGF	10 ng/mL
Pen/Strep	1x
Mammary Organoid Medium
Advanced DMEM:F12
B27	1x
GlutaMax	1x
heparin	4 µg/mL
Hepes	1x
human Noggin	100 ng/mL
murine bEGF	20 ng/mL
murine EGF	50 ng/mL
R-Spondin 1	1 µg/mL