Simple Silica Column-Based Method to Quantify Inorganic Polyphosphates in Cartilage and Other Tissues

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Inorganic polyphosphates (polyP) are crucial molecules in mammalian biology with diverse functions.
• Existing methods for quantifying polyP are often insensitive or complex, hindering research.
• Mammalian tissues, like cartilage, contain interfering macromolecules that complicate polyP determination.

Purpose of the Study:

• To develop a simple, sensitive, and robust method for quantifying low levels of inorganic polyphosphates (polyP) in mammalian tissues.
• To address the limitations of current polyP quantification techniques, particularly in complex biological matrices.

Main Methods:

• Tissues were digested with proteinase K to release polyP.
• PolyP was isolated and purified using silica spin columns.
• Quantification was performed using DAPI fluorometry, assessing fluorescence shifts indicative of polyP presence.

Main Results:

• Proteinase K treatment enhanced polyP recovery by reducing protein interference.
• Nuclease treatment and Tris buffer addition effectively removed contaminating nucleic acids and glycosaminoglycans.
• The developed method achieved over 80% polyP recovery and detected levels as low as 10^-10 mol.

Conclusions:

• A sensitive, reproducible, and user-friendly method for quantifying polyP in mammalian tissues has been established.
• This technique is valuable for advancing the study of polyP's biological roles in cells and tissues.
• The method's applicability extends to various biological sources, including fluid samples like blood and serum.