1. Infrared electroabsorption spectrometer
(home made with CT-50 (JASCO))
Dispersive IR spectrometer is used in this laboratory, because the dispersive IR spectrometer realizes detection of quite small changes in IR absorption (ΔA) due to repetative perturbation. AC coupling technique enables it: the AC coupling technique is a method to selectively amplify AC components in the signal output (Figure).
Change in the IR absorption is calculated from the transmitted light intensity without perturbation (Ioff) and the change in the intensity caused by the perturbation (ΔI). Ioff is measured by modulating the intensity of incident light with a chopper (Fig.(a)).
ΔI due to the perturbation may be much smaller than Ioff (Fig. (b)), and precise determination of Ioff is difficult in such a case. In order to measure the ΔI signal, we eliminate DC component (i.e., Ioff) (Fig. (c)) and amplify the remaining AC component (Fig. (d)). This procedure, so called AC coupling method, enables us to measure the ΔI component precisely. We detected the ΔA signal as small as 6 x 10-8 (unpublished data).
2. 785 nm-Excited Portable Raman Spectrometer (BaySpec)
It enables us to measure Raman spectrum not only in the laboratory but also outside.
3. Automated microwave peptide synthesizer (Initiator+ Alstra, Biotage)
Peptides are natural/artificially manufactured short chains of the amino acids linked by the peptide bonds. The peptides are subjected to study structures/functions of the proteins. This is an equipment for automatic synthesis of peptides having arbitrary sequences. It is based on solid-phase peptide synthesis using Fmoc chemistry with the aid of microwave heating.
4. High-performance liquid chromatography, HPLC (LC-4000, JASCO)
HPLC is used for the sample purification. Samples are usually applied to the spectroscopic analyses by making their purity high enough as to discuss/conclude something about them.
5. Lyophilizer (FDM-5, Uniss)
This equipment removes H2O from frozen samples.