Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics

Table 1

Main characteristics of chemical and mechanical methods to extract nucleic acid (adapted from Harrison 2003).

Method	Technique	Principle	Mode of lysis	Cost	Most usual application	References
Chemical	Osmotic shock	Osmotic rupture of membrane	Gentle	Cheap	Spheroplasts and Protoplasts	[9]
	Enzymatic digestion	Digestion of cell wall	Gentle	Cheap at small scale; expensive at large scale	Gram-positive and Gram-negative bacteria	[13]
	Detergents	Solubilization of membranes	Gentle	Moderate	General use	[14]
	Alkali treatment	Solubilization of membrane	Harsh	Cheap	Plasmid DNA	[15]
Mechanical	Homogenization (blade or pestle)	Shredding of cells	Moderate	Moderate (method of choice for large scale)	Animal tissues	[10]
	Ultrasonication or cavitation	Disruption of cells by pressure	Harsh	Moderate to expensive	Good for spheroplasts but not primary cells	[11, 12]
	Pressure cell (“French press”)	Disruption of cells by shear force	Harsh	Moderate	Used for Gram-negative and some Gram-positive bacteria	[6]
	Ball mill	Cells crushed between glass/steel balls/beads	Harsh	Cheap	Used for bacteria, yeast, microalgae, unicellular animal cells	[15]