Lysates

A lysate is a suspension containing the contents of cells or tissues after the plasma membrane has been disrupted. It typically includes proteins, nucleic acids, lipids, and organelles, depending on the disruption method. Lysates are contrasted with purified cellular components because they preserve a broader complement of cellular constituents, though they lose native compartmentalization.

Lysates are generated by disrupting cells via chemical, enzymatic, or mechanical methods. Chemical lysis uses detergents and salts; mechanical methods include homogenization or sonication; enzymatic uses enzymes like lysozyme to weaken cell walls. In all cases, protease inhibitors are commonly included to limit protein degradation. Crude lysates contain most cellular material, while clarified lysates are obtained by centrifugation to remove insoluble debris.

Lysates serve as sources for biochemical and molecular assays, including proteomics, Western blotting, immunoprecipitation, enzyme activity assays, and PCR templates. They enable analysis of proteins and transcripts in a context-rich mixture, though they can also contain interfering substances that affect measurements. Choice of lysis method and buffer conditions can influence protein solubility and activity, and may bias which components are represented.

Storage and handling focus on preserving integrity; lysates are often kept on ice for short-term use and stored at ultra-low temperatures for long-term use, with aliquoting to avoid repeated freeze-thaw cycles. They require appropriate biosafety practices consistent with the tissue source and experimental goals.