A multi-sample microdialysis apparatus for proteins and nucleic acids

A multiposition microdialysis system suitable for simultaneous microsample applications (between 10 microL and 500 microL), has been developed. Each sample, contained in a specially designed microfuge dialysis tube (mDT), is dialysed independently from the other samples. Each mDT has its own membrane, and this feature allows the use of different membranes and dialysis times for different samples. The microdialysis apparatus is kept at constant temperature by an external thermostat, avoiding the use of a cold box. The dialysis release time for small ions, a parameter used for quantitation of microdialysis efficiency, decreases from 22.9 min (for a 200 microL sample) to 7 min (for a 50 microL sample). The sample is efficiently recovered by centrifugation. Quantitative recoveries (90%) of different proteins and DNA were achieved after microdialysis by mDT.