Expression of fibrocartilaginous markers at P3 versus D21. Inner and outer MFCs were expanded to Passage 3 (P3, white bars) then chondrogenically stimulated in scaffold culture under 21% or 3% O2 in vitro for 21 days (D21, hatched bars). mRNA transcript expression levels were analyzed for collagen type I (Col1), collagen type II (Col2), aggrecan and cartilage oligomeric matrix protein (COMP). Expression was normalized to levels of the housekeeping gene β-actin using 2-ΔCT method. * = p < 0.05 ** = p < 0.01 represents significant difference between P3 and D21 values within groups using Student’s two-tailed t-test. There was no significant difference in expression levels of these mRNA transcripts between D21 scaffold constructs from inner or outer MFCs cultured under 21% or 3% oxygen tension. # = p <0.05 by one-way ANOVA with Games-Howell multiple comparisons post-test.