the concentration of fibronectin in fetal lung tissue obtained at different days of gestation was determined using a specific enzyme-linked immunoadsorbent assay ( elisa ) and was found to increase from 1.7 ng/micrograms protein in fetal lung tissue obtained at day 19 of gestation to 7.3 ng/micrograms protein in fetal lung tissue obtained at day 24 of gestation .
C0024109
lung
C0819757
lung tissue