Blastomere In Situ Hybridization

Antibody	An antibody is formed to bind to a particular gene product.
Label	The antibody is labeled so it is easily visible when bound to its antigen.
2-8 Cells	Until the 2-8 cell stage, gene expression is consistent in all cells.
Later	After the 2-8 cell stage, gene expression begins to vary from cell to cell.
Conclusion	Loss of totipotency is due to differential gene expression. All cells remain genomically equivalent, though different genes become activated in different cells.