Spacer Arm in Affinity chromatography

Spacer arm is an important part of the stationary phase of the affinity chromatography. In the affinity chromatography, the stationary phase has the following component.

Solid Matrix, Ligand, and the Spacer Arm.

Definition of the spacer arm:

Spacer arms are the aliphatic, linear hydrocarbon chain and or other atoms with two functional group one at each end of the chain and other is attached to the ligand.

Spacer arms are covalently bound to the solid matrix and away from the solid matrix. 

In some molecule the active side is available (located) deep within the sample molecule and difficult to access steric hindrance. It’s too difficult to achieve the proper purification or the separation of the analyte from the sample, when the active site cannot attach with the ligand.

The characteristic of the spacer arm:

The length of the chain should be enough, It should not be too short or long The length of the spacer arm is a critical parameter With the short or long length proper binding is not achieved.

It should not have the nonspecific binding.

Spacer the arm should have the

There are two possibilities to attach the Spacer arm with the sample molecule:

 One case one end of the spacer arm is 1^st bound to the matrix and biological ligand attaché to the other end of the spacer arm using different methods. Hence active site of the molecule directly attached to the ligand.

In second case the 1^st bound to the ligand as substitutes and then another end of the spacer can be fixed the matrix.