The Best Lab Ultrafiltration Practices
Soak/Wash membrane with ultrapure water to remove glycerol to final 3 µg Carbon (CHN Analyzer)
Unlike microfiltration membranes, keep the UF membrane wet. The pores will close if allowed to dry in absence of glycerol.
Consider pH tolerance of plastic & membrane! Polycarbonate is not tolerant above pH 9
Using UF for protein retention or contaminant removal requires an understanding of how UF operates.
Diafiltration: 10:1 (3x) volume exchange is the fastest method for 99.9% buffer exchange.
Performance: % Protein recoveries are improved with the Proteus X-spinner 2.5. Up to 98% protein recoveries were observed with 2.5 ml hydrophobic protein concentrated to 0.25 ml at 2,500 g.