A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent

Gerrit Haeger; Johannes Bongaerts; Petra Siegert

doi:10.1016/j.ab.2022.114819

A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent

Anal Biochem. 2022 Oct 1:654:114819. doi: 10.1016/j.ab.2022.114819. Epub 2022 Jul 15.

Authors

Gerrit Haeger¹, Johannes Bongaerts¹, Petra Siegert²

Affiliations

¹ Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany.
² Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, 52428, Jülich, Germany. Electronic address: siegert@fh-aachen.de.

PMID: 35839914
DOI: 10.1016/j.ab.2022.114819

Abstract

An improved and convenient ninhydrin assay for aminoacylase activity measurements was developed using the commercial EZ Nin™ reagent. Alternative reagents from literature were also evaluated and compared. The addition of DMSO to the reagent enhanced the solubility of Ruhemann's purple (RP). Furthermore, we found that the use of a basic, aqueous buffer enhances stability of RP. An acidic protocol for the quantification of lysine was developed by addition of glacial acetic acid. The assay allows for parallel processing in a 96-well format with measurements microtiter plates.

Keywords: 96-Well format; Air-stability; Amino acid-releasing enzymes; Aminoacylase assay; N(ε)-acyl-lysines; Ninhydrin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acids*
Indicators and Reagents
Ninhydrin*

Substances

Amino Acids
Indicators and Reagents
Ninhydrin