Photometric Measurement of Mixing Efficiency Using The Eppendorf MixMate Plate Mixer


Efficient mixing of solution components is a critical step in the performance of certain assay types.  As more life science and pharmaceutical laboratories conduct their assays in 96- and 384-well plate formats, mixing issues within these plates are becoming more common than ever before. However, these plate formats and their special geometries, in combination with reduced reaction volumes, place very specific demands on efficient mixing. Particularly 384-well plates present some difficult mixing challenges for classical mixers.

In an effort to find a mixing device that optimally mixed in 384-well microtiter plates, Artel performed an evaluation of the Eppendorf MixMate plate mixer. Instead of relying upon subjective visual observations, Artel developed a quantitative dual-dye absorbance method to assess the capabilities of the Eppendorf MixMate. In this method, two dye-containing solutions (a sample solution plus a diluent solution) were dispensed into the same wells of a 384-well microtiter plate. Absorbance values of the dyes in each well were photometrically measured before and after mixing. A premixed combination of the two dye-containing solutions was used as a Control to account for any potential non-mixing related artifacts. The relative variation in average absorbance and coefficient of variation (CV) computed over multiple mixing trials provide data regarding the mixing efficiency of the device.

In this poster presentation, we describe in detail the dual-dye measurement method.  We also demonstrates the ability of the Eppendorf MixMate to completely mix test samples in a 384-well plate in less than one minute.

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