Embodiments of the invention include instruments and methods useful in preparing and delivering graft material to a surgical site. Some embodiments may particularly be directed to forming a graft from a blood clot and accurately and effectively handling and delivering the graft to a surgical site. Graft material may include blood components such as clotted fibrin derived from a patient's or a donor's blood.

There is provided a method of sampling an aliquot of blood products from a main container containing the blood products to be sampled. The method includes providing a sample container that is rectangular-shaped and has a length-over−width (L/W) ratio of at least that of the main container, and fluidly connecting the a sample container to the main container, transferring the aliquot of the blood products from the main container to the sample container, and forming an air bubble in the sample container by introducing a volume of air into the sample container with the aliquot of the blood products. The volume of air forming the air bubble corresponds to at least about 5% of a volume of the aliquot of the blood products. A sampling bag and a sampling system are disclosed.

Embodiments of the invention include instruments and methods useful in preparing and delivering graft material to a surgical site. Some embodiments may particularly be directed to forming a graft from a blood clot and accurately and effectively handling and delivering the graft to a surgical site. Graft material may include blood components such as clotted fibrin derived from a patient's or a donor's blood.