Abstract: A micro-machined nuclear transfer array (NTA) provides high-throughput transfer of nuclei between two cells. Donor cells containing the nuclei to be transferred are placed in microwells positioned adjacent to microwells containing the recipient biological cell. The microwells are contained within an upper chamber patterned with parallel rows of microwells of the diameter of the cell of interest. An injection port is formed in the bottom of the microwells through which nuclei may pass during transfer. The NTA also contains a lower chamber having a second array of capture wells of similar dimension and in register with the upper chamber for receiving the nuclei removed from the cell in the upper chamber. Nuclei are removed from the donor cells in the upper chamber, transferred to capture wells in the lower chamber, and inserted into the recipient biological cells of the upper chamber.

Abstract: One aspect of the invention is the method of operating a microphysiometer including a plunger assembly having a plunger body with a microchamber at one end for receiving a sample and a passage in the plunger body communicating with the microchamber comprises passing a medium transversely through the-sample in the microchamber. Another aspect of the invention is the construction of the plunger assembly wherein the sample is positioned in the microchamber and the passage and microchamber are constructed and arranged so that medium flow is transverse through the sample. The sample may be a tissue slice retained between a pair of screens or membranes, adherent cells on a mesh screen or non-adherent cells retained in a chamber defined by a washer and a pair of screens or membranes.