| pubmed-article:520505 | pubmed:abstractText | When a serumless medium is used for the in vitro growth and development of post-blastocyst mouse embryos, a collagen substratum causes a delay in the hatching from the zona pellucida. However, the collagen substratum is essential for blastocyst attachment and trophoblast cell outgrowth after hatching has taken place. | lld:pubmed |
