Acetone serves as a potent organic solvent in biochemistry laboratories, particularly for protein precipitation and lipid delipidation. Its low dielectric constant and capacity to disrupt hydrophobic interactions make it highly effective for separating biomolecules and preparing samples for downstream analytical applications.

Chemical Properties

Acetone ((CH₃)₂CO) is the simplest ketone, characterized by a central carbonyl (C=O) group flanked by two methyl groups in a planar configuration. It has a boiling point of 56°C and is fully miscible with water, ethanol, and chloroform. With a density of 0.785 g/mL at 20°C and a vapor pressure of approximately 30 kPa, acetone evaporates rapidly under ambient conditions. It exhibits keto–enol tautomerism, although the enol form represents less than 0.0003% at equilibrium, ensuring chemical stability in most laboratory protocols. High-purity analytical grades (ACS/HPLC ≥99.5%) minimize water and benzene impurities, making acetone suitable for chromatography and sensitive analytical techniques.

Biochemical Applications

In proteomics workflows, ice-cold acetone (typically 4:1 v/v relative to sample volume) efficiently precipitates proteins from lysates or gel extracts, achieving recovery rates above 90%. The mechanism involves dehydration of solvation shells and aggregation mediated by van der Waals interactions, facilitating sample preparation for mass spectrometry. In lipid biochemistry, acetone is used to wash Folch extracts to remove non-lipid contaminants following chloroform–methanol extraction, and to delipidate membrane fractions prior to electrophoretic analysis. In molecular biology applications, acetone fixation preserves cellular morphology for immunofluorescence without the permeabilization effects associated with methanol, and it assists in nucleic acid purification from polysaccharide-rich plant tissues.