Cell nucleus membrane. Transmission electron micrograph (TEM) of a section through part of the nuclear membrane of a kidney cell revealing its nuclear pores. The curved double membrane (dark grey) is at far right, with rounded nuclear pores seen at centre and upper right. Assorted nuclear contents are also visible. The pores allow large molecules to be actively passed between the nucleus and the surrounding cytoplasm. The nuclear membrane encloses the nucleus which contains the cell's genetic material. Magnification: x100,000 at 8x10 inch size.