Problems associated with "in vivo" culture of early stages of micromanipulated embryos from large domestic animals include: 1) Various technical steps of agar embeddation that are labor intensive; 2) incomplet agar coating of the embryo resulting in invasion of alien cells and/or dispersal of blastomeres; and 3) the need of a temporary recipient until the embryo reaches the blastocyst stage of development. Encapsulation of micromanipulated embryos in a biodegradable calcium alginate gel may simplify and improve efficiency of culture of embryos in the early stages of development in the female reproductive tract.Five (5-8 celled) radically micromanipulated swine embryos were drawn up into a micropipette containing 1.1% sodium alginate. The contents were expelled into a 1.5% calcium chloride solution which gelled the spherical droplet. The capsule was then transferred into a definitive recipient. Encapsulated micromanipulated and control embryos were observed at 28 days of pregnancy ot assess implantation rates.When following this protocol it is possible that the calcium alginate matrix affords the micromanipulated embryo protection against physical damage, dispersal of blastomeres, invasion of alien cells, and normal developmental rate during the early stages.National Institute of Child and Human Development (NICHD)