Method for the extraction of a factor that mediates contact inhibition of cell growth
AssigneeNew York University
InventorMartin J. Rosenberg
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Abstract
Described herein is a method for the extraction of an active biochemical factor that restores contact inhibition of growth to malignant cell types of different mammalian species.
Claims20
A method for the isolation of a biologically active factor that restores contact inhibition of growth to malignant cell types which comprises
- applying a sample comprising media conditioned by growth of a contact inhibited cell culture to a fractionating column comprising a non-ionic hydrophobic affinity material, the hydrophobic binding interaction of said material with proteins capable of being modified in the presence of buffers of varying ionic strength,
- sequentially eluting the column with buffers of decreasing ionic strength,
- applying unbuffered distilled water to said column as the final eluting medium,
- collecting the unbuffered distilled water eluate from said column,
- lyophilizing the eluate to a powder,
- dissolving the powder in distilled water to form a solution, and
- adding ethanol to the solution to form a precipitate comprising said factor, said factor having a UV peak absorbance at about 280 mm being non-dialyzable, hydrophobic and water soluble.
A composition comprising a contact inhibition factor that restores contact inhibition of growth to malignant mamalian cell types, said composition being prepared by applying a sample comprising media conditioned by growth of a contact inhibited cell culture to a fractionating column comprising a non-ionic hydrophobic affinity material, the hydrophobic bonding interaction of said material with proteins capable of being modified in the presence of buffers of varying ionic strength,
- sequentially eluting the column with buffers of decreasing ionic strength,
- applying unbuffered distilled water to said column after eluting with said buffers of decreasing ionic strength,
- collecting the material eluting with the distilled water,
- lyophilizing the distilled water to said column after eluting with said buffers of decreasing ionic strength,
- collecting the material eluting with the distilled water,
- lyophilizing the distilled water eluant to a powder,
- dissolving the lyophilized powder in distilled water to form a solution,
- adding ethanol to said solution to form a precipitate comprising said factor, and
- collecting said solid precipitate, said factor having a positive reaction in the Lowery assay for protein, being active to restore contact inhibition of growth in cultures of non-contact inhibited cells a UV peak absorbance at about 280 nm, being non-dialyzable, hydrophobic and water soluble and having a molecular weight in excess of 10,000 Daltons.
Dependencies are inferred from the claim text.