High-Throughput Microplate Reader Cuts Down Screening Time

EKKO, a new, high-throughput circular dichroism (CD) microplate reader, demonstrates a faster processing time than current screening methods. The technology was launched in November 2018 by Bio-Logic Science Instruments, a French designer and manufacturer of high-performance laboratory research instruments and software, and Hinds Instruments, a US provider of polarization measurement instrumentation. 

The device is compact and can screen a 96-well plate in under two minutes, as opposed to several hours compared to a traditional CD spectrometer linked to an auto sampler, the companies report. The device is also cost efficient, using 10 times less nitrogen than a standard spectropolarimeter with auto sampler and four times fewer samples at a comparable light path, they state.

As a result, the technology offers a significantly faster timeframe than supercritical fluid chromatography (SFC) and ultra-high-performance liquid chromatography (UHPLC) protocols. The device is also able to identify enantiomeric excess (ee) rates and yield data that can prove highly beneficial to the screening process. There is also an environmentally friendly aspect to the new device since it requires no solvents.

“This CD reader eliminates the time-consuming process of transferring the contents of each well of the micro-well plate into a cuvette, and cleaning between each measurement, as is necessary when using conventional CD spectrometers.  Furthermore, by avoiding chromatography completely, EKKO is well suited to identifying ‘hits’ quickly using high-throughput screening,” said Bob Wang, senior scientist at Hinds, in a company press release.

The device is said to be the first commercially-available system of its kind, according to the companies. “EKKO is a technological response to help develop chirally pure pharmaceuticals. It is as easy to use as any standard fluorescence or absorbance microplate reader and can add significant value to any laboratory where rapid chiral analyses are needed. We have received excellent market feedback and an academic paper has already been published demonstrating the technology’s efficiency at determining enantiomeric excess during trials,” said Cedric Georges, product manager, Bio-Logic, in the press release.

“The EKKO system is the only instrument on the market that allows the direct reading of CD spectra and ellipticity values in 96 and 384 well plate formats. Thus, the handedness and-with proper standards and assays-the enantiomeric excess of reactions can be read in parallel, thereby allowing very rapid assays for examining asymmetric reaction screening during high-throughput experimentation. Furthermore, because CD is the tool of choice for following protein folding, it enables the screening of pharmaceutical interactions with proteins in parallel, generating another approach to high-throughput lead discovery in the pharma industry,” added Professor Eric V. Anslyn, co-author of the published Bio-Logic academic paper.

Regulatory challenge

As more is understood about the importance of chiral properties of drugs, FDA and other agencies have made increasing demands that drug companies fully separate, characterize, and control the enantiomers they sell. The differences between two enantiomers of a molecule are chemically subtle, however, so separation and characterization are difficult, which has led to a requirement for more analytical methods that can differentiate between enantiomers and help provide quality control.

CD instruments, though available for many years, are all designed to measure the CD of a single reaction product at a time. The EKKO device offers the capability to rapidly “read” the enantiomeric composition of 96 reaction products in a standard laboratory micro well plate, which amounts to approximately thousands of readings per day. It is ideally suited to parallel/combinatorial synthesis techniques where more test combinations can be carried out in less time, according to the companies.

In addition, the device also provides flexibility in that its optics can work at ultraviolet levels as far down as 185nm, making it suitable for determining secondary protein structures, for biotherapeutic development, or for formulation optimization.

Source: Bio-Logic