LBP and CD14 expression in the mouse mammary gland. (a) Western blot for LBP and CD14. Protein extracts from mouse mammary glands from the developmental stages virgin 12 weeks, pregnancy days 1, 2, 3, 8.5, 12.5 and 17.5, lactation days 1, 3 and 7, and involution days 1, 2, 3, 4 and 20 were separated on a denaturing gel; Western blotting was performed with anti-LBP, anti-CD14 and anti-β-actin antibodies. (b) Localisation of CD14 protein by immunohistochemistry. Paraffin-embedded sections from 7 days lactating (i, ii) and 2 days involuting (iii, iv) mouse mammary glands were stained with an anti-CD14-specific antibody. Negative controls contained no primary antibody.