Assays Based on FTIR Spectroscopy for Assaying Lipases or Esterases

Assays Based on FTIR Spectroscopy for Assaying Lipases or Esterases 

The analysis of IR spectra of different synthetic mixtures of C-labeled and non-labeled enantiomeric actetates poses no problems. After applying an automated baseline correction to the spectra and correcting the absorbance of one enantiomer in the synthetic mixtures by the absorbance of the other enantiomer at this position, the accuracy of the /i.seMJo-enantiomeric system is excellent, specifically, within +3% in comparison to the ee values determined by chiral GC 101). Using commercially available HTS-FTIR systems, high-throughput measurements are easily possible. The analysis can be performed on a Tensor 27 FTIR spectrometer coupled to a HTS-XT system, which is able to analyze the samples on 96- or 

384-well microtiter plates. The plates are equipped with a silicon plate for IR transmittance. Moreover, the ee values can be measured in culture supernatants, which is not possible in the case of the MS- or NMR-based assays. The manufacturer Bruker has already coupled the microplate stacking device TWISTER 1 to its microplate reader 101). In this combination which is controlled by OPUS software, 40 IR microplates can be measured automatically. In order to perform the sample loading at high throughput, the autosampler microlab 4000 SP can be used. Both formats (96 and 384) of the Bruker silicon microplates are suitable for automatic loading of different types of samples (proteins, cells, and culture media). At least 9000 samples can be handled per day 101). 

---