Our amine-to-amine crosslinker is a homobifunctional amine-specific protein crosslinking reagent that uses NHS-ester and imidoester reactive groups for selective conjugation of primary amines. Our amine-to-amine crosslinkers are available in short, long, cleavable, irreversible, membrane permeable, and cell surface varieties.

Our amine reactive crosslinkers have a variety of useful characteristics:

NHS-ester crosslinkers

  • Amine-specific crosslinking reagents based on N-hydroxysuccinimide ester (NHS ester) reactive chemistry
  • NHS esterreactive groups are formed by EDC-activation of carboxylate molecules
  • NHS ester-activated crosslinkers and labeling compounds react with primary amines in slightly alkaline conditions (pH 7.2-8.5) to yield stable amide bonds

Imidoester crosslinkers

  • Traditional amine-reactive crosslinking reagents based on the imidoester reactive group
  • Imidoester crosslinkers react with primary amines to form amidine bonds
  • Best when used in amine-free, alkaline conditions (pH 10), such as with borate buffer, to provide specificity for primary amines

Other amine-reactive crosslinkers

  • We offer specialized crosslinking reagents and kits for amine-specific molecular conjugation and polymerization based on phosphine, aldehyde, or aryl halide reactive groups.
Reactive Group Products Spacer Arm (Å) Cleavable? Water-soluble? Membrane-permeable? Reversible?
NHS ester DSG 7.7 N/A No Yes No
DSS   11.4 N/A No Yes No
BS3 11.4 N/A Yes No No
TSAT (trifunctional) 4.2 N/A No No No
BS(PEG)5 21.7 N/A Yes No No
BS(PEG)9   35.8 N/A Yes No No
DSP   12.0 Thiols No Yes No
DTSSP   12.0 Thiols Yes No No
DST   6.4 Periodate Yes Yes No
BSOCOES 13.0 Base No Yes No
EGS   16.1 Hydoxylamine No Yes Yes
Sulfo-EGS   16.1 Hydoxylamine Yes No Yes
Imidoester DMA  8.6   N/A Yes Yes Yes
DMP  9.2 N/A Yes Yes Yes
DMS 11.0 N/A Yes Yes Yes
DTBP 11.9 Thiol Yes Yes No
Difluoro DFDNB 3.0 N/A No Yes Yes

We also offer Molecular Probes® N-(t-BOC)-Aminooxyacetic Acid, Tetrafluorophenyl Ester, which is an amine-reactive protected hydroxylamine that is useful for synthesizing new aldehyde- and ketone-reactive probes in an organic solvent. Following coupling to aliphatic amines, the t-BOC group can be quantitatively removed with trifluoroacetic acid.