N-Isobutyryl-L-cysteine is a thiol compound, which distinguishes chirality in assays involving amino acids with OPA. N-Isobutyryl-L-cysteine is employed along with gold particles on a monolayer surface to separate single stranded DNA, via the interaction between the dipole moment of N-Isobutyryl-L-cysteine and the negative charge of single stranded DNA. These studies determined that N-Isobutyryl-L-cysteine is an essential tool along with gold nanoparticles in vibrational circular dichroism (VCD) and circular dichroism (CD) spectroscopy. Furthermore, the L isomer is more effective in adsorption of relaxed DNA compared to the D form which causes DNA to supercoil and results in a weaker binding strength.
