The stain in question enters dead cells easily, but cannot enter living ones.

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They work only with dead cells or pieces of a cell, never capturing crucial data about how drugs affect living cells.

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The outer layer of an elephant tusk is packed with dead cells.

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Researchers can only use dead cells or pieces of a cell and can only test for one response at a time, such as enzyme activity or the binding of a compound to a receptor.

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Lymphomas are cancers of the lymphatic system, a network of vessels which form part of the body's immune system, and carry other infection-fighting cells called "lymphocytes", as well as draining dead cells away from the tissues.

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The lactic acid in it supposedly helps dissolve dead skin cells and aids cellular regeneration.

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That is when the virus releases its attack, spreading when the dead skin cells flake off the body naturally.

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Although there is no way, yet, to revive dead brain cells, attempts are under way to use old Parkinson's disease drugs that boost levels of the neurotransmitter dopamine or mimic its effects.

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It sounds like you're describing tonsillar stones (also called tonsilloliths), which are clumps of food particles, mucus, dead tissue cells and more that can collect in the crypts found on the surface of the tonsils.

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The long-term hope is to treat patients with some sort of stem cell that could turn into beating heart muscle and replace dead cardiac tissue with fully functioning new cells.

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