Malvern Instruments’ new improved folded capillary cell enhances zeta potential measurement

Malvern Instruments has introduced a new, improved disposable folded capillary cell for use in its Zetasizer Nano particle and molecular characterization systems. The new DTS1070 replaces the previous model of folded capillary cell, the DTS1061, and has been designed to further enhance the reproducibility of zeta potential and protein mobility measurements, while providing the same ‘plug and play’ convenience for easy application and disposal. The production process for the DTS1070 has also been improved to minimise the time from order placement to delivery. 

The folded capillary cell is fundamental to Malvern’s patented diffusion barrier technique for the reliable, high-sensitivity measurement of the electrophoretic mobility (or zeta potential) of labile biological molecules, such as proteins in solution. Using this technique, the sample is separated from the electrodes in order to avoid aggregation under the influence of the applied electric field. This is done by filling the cell with buffer, then introducing a small volume of sample into the measurement zone. In addition, the ability to measure size in the same cell before and after a zeta potential measurement enables checks to be made that ensure zeta potential measurement has not been affected by any aggregation of the sample.

Conventionally, a long linear capillary cell is used when measuring zeta potential in order to separate the measurement zone from the electrodes and to provide a sufficiently long surface for the development of a smooth electro-osmotic profile. Malvern’s folded capillary cell has all the advantages of a linear capillary cell while being completely disposable, for applications where there might otherwise be a risk of cross-contamination.

There are subtle differences between the DTS1070 and DTS1061 cells, for example the position of the inlet ports, however the performance of the two is identical, and no difference in results will be observed when changing over to the new cells. It is essential for use of the new DTS1070 that you user Zetasizer software version 7.02 or later, as the DTS1070 will not appear as an option in the cells selection screen of previous versions of software. For more information, please read the Technical Note.

The DTS1061 cells will be discontinued at the end of 2013 when stocks have been exhausted, therefore please change over to the new DTS1070 cells as soon as possible. Those customers that may have difficulties in changing to the new cells in that time frame should contact their local representative for advice or email   


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