Peptide immobilisation - spacer length?

[Michael Daws]

I am going to attach a peptide to an aminoalkyl agarose support using a
bifunctional cross linker - does anyone know what the best spacer length
would be to limit steric hindrance.  Presumably if the hydrophobic
spacer is too long it will allow increased non-specific binding or
spacer cleavage?

Thanks.

Mike Daws