Abstract: Provided is a method for obtaining high-yield, stable expression cell clones from myeloma cell lines in a protein-free culture medium. The method is used for industrial production of a recombinant antibody, and includes three stage: (1) adapting to a protein-free culture medium, statically culturing cells at a low density, and gradually reducing a fat-rich supplement to a chemical culture medium; (2) adapting to a protein-free culture medium; culturing cells at a high density, and using a perfusion fermentation system in a laboratory scale; and (3) screening high-yield, stable expression cell clones from the cells after fermentation ends. The cell clone may be used to produce a humanized anti-NeuGcGM3 14F7 recombinant antibody.

Abstract: A travel-proofed portable computer keyboard with keys sealed against dust and minor impacts includes an alphanumeric keyboard, a numeric keypad, and a first locking mechanism. The alphanumeric keyboard includes an open cavity. The numeric keypad is received in or protruding from the cavity. The numeric keypad includes a first notch and a second notch. The first locking mechanism includes an engaging member which can lock the numeric keypad in place. The numeric keypad is held in the cavity of the alphanumeric keyboard when the engaging member engages the first notch of the numeric keypad, thereby facilitating the carrying of the computer keyboard. The numeric keypad is held to protrude from the cavity of the alphanumeric keyboard when the engaging member engages the second notch of the numeric keypad, thereby enabling the use of the computer keyboard.

Abstract: A travel-proofed portable computer keyboard with keys sealed against dust and minor impacts includes an alphanumeric keyboard, a numeric keypad, and a first locking mechanism. The alphanumeric keyboard includes an open cavity. The numeric keypad is received in or protruding from the cavity. The numeric keypad includes a first notch and a second notch. The first locking mechanism includes an engaging member which can lock the numeric keypad in place. The numeric keypad is held in the cavity of the alphanumeric keyboard when the engaging member engages the first notch of the numeric keypad, thereby facilitating the carrying of the computer keyboard. The numeric keypad is held to protrude from the cavity of the alphanumeric keyboard when the engaging member engages the second notch of the numeric keypad, thereby enabling the use of the computer keyboard.

Abstract: Provided is a method for obtaining high-yield, stable expression cell clones from myeloma cell lines in a protein-free culture medium. The method is used for industrial production of a recombinant antibody, and includes three stage: (1) adapting to a protein-free culture medium, statically culturing cells at a low density, and gradually reducing a fat-rich supplement to a chemical culture medium; (2) adapting to a protein-free culture medium; culturing cells at a high density, and using a perfusion fermentation system in a laboratory scale; and (3) screening high-yield, stable expression cell clones from the cells after fermentation ends. The cell clone may be used to produce a humanized anti-NeuGcGM3 14F7 recombinant antibody.