What are the differences between agarose and polyacrylamide?

Question

Accepted Answer

Basis of differentiation

Agarose

Polyacrylamide

Definition

Is a natural gel and the main constituent of agar used especially in gels for electrophoresis

Is a synthetic resin made by polymerizing acrylamide - a water-soluble polymer used to form a stabilized gel

Synthesis

Is a complex polysaccharide derived from seaweed

Is produced by the digestion of acrylonitrile by nitrile hydratase

Composition

Is composed of many molecules

Is composed of one large molecule

Gap size between molecules

Has wide gaps between the differently-sized molecules

Has smaller gaps between the uniformly-sized molecules

Gels

Agarose gel is natural and composed of long chains of interlinked sugars to form a meshwork

Polyacrylamide gel is synthetic and composed of chemical crosslinking of acrylamide and bis-acrylamide, producing a molecular sieve

Pore Size

The pores of the agarose gel become smaller in size with the increasing concentration of agarose in the gel

The pore size of the polyacrylamide gel is determined by the ratio of acrylamide to bis-acrylamide

Setting

Sets as it cools – this is purely a physical change

Sets after crosslinking occurs – this is a chemical change

Orientation of pour

Is poured horizontally

Is poured vertically

Typical concentrations of the gel

0.5% to 2%

6% to 15%

Application

Used for separating much larger DNA fragments such as the products of PCR

Used for separating proteins and small nucleic acids such as miRNA, oligonucleotides, tRNAs, etc

DNA fragment size

Separate DNA about 50 – 20,000 bp in size

Separate DNA about 5 – 500 bp in size

Resolving power

Have a comparatively low resolving power

Have a high resolving power

DNA configuration

Separate DNA in the double-stranded form

Separate DNA in the single-stranded form

Toxicity

Is considered entirely non-toxic

moderately hazardous and require protection during handling

Basis of differentiation	Agarose	Polyacrylamide
Definition	Is a natural gel and the main constituent of agar used especially in gels for electrophoresis	Is a synthetic resin made by polymerizing acrylamide - a water-soluble polymer used to form a stabilized gel
Synthesis	Is a complex polysaccharide derived from seaweed	Is produced by the digestion of acrylonitrile by nitrile hydratase
Composition	Is composed of many molecules	Is composed of one large molecule
Gap size between molecules	Has wide gaps between the differently-sized molecules	Has smaller gaps between the uniformly-sized molecules
Gels	Agarose gel is natural and composed of long chains of interlinked sugars to form a meshwork	Polyacrylamide gel is synthetic and composed of chemical crosslinking of acrylamide and bis-acrylamide, producing a molecular sieve
Pore Size	The pores of the agarose gel become smaller in size with the increasing concentration of agarose in the gel	The pore size of the polyacrylamide gel is determined by the ratio of acrylamide to bis-acrylamide
Setting	Sets as it cools – this is purely a physical change	Sets after crosslinking occurs – this is a chemical change
Orientation of pour	Is poured horizontally	Is poured vertically
Typical concentrations of the gel	0.5% to 2%	6% to 15%
Application	Used for separating much larger DNA fragments such as the products of PCR	Used for separating proteins and small nucleic acids such as miRNA, oligonucleotides, tRNAs, etc
DNA fragment size	Separate DNA about 50 – 20,000 bp in size	Separate DNA about 5 – 500 bp in size
Resolving power	Have a comparatively low resolving power	Have a high resolving power
DNA configuration	Separate DNA in the double-stranded form	Separate DNA in the single-stranded form
Toxicity	Is considered entirely non-toxic	moderately hazardous and require protection during handling

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