Microporous Sample Prep
At every stage of the drug discovery process, samples must
be isolated, purified and prepared prior to testing.
Automation-compatible MultiScreen Filter Plates are used in a range of
applications. Membranes and plastic are optimized for use in applications
including sample cleanup prior to instrument analysis, removal of cellular
debris, extraction of natural products, and bead cleavage assays.
For general sample prep, protein precipitation assays with solvents, bead
cleavage assays, and quantitative filtrate transfer suitable for instrumental
analysis, MultiScreen Solvinert filter plates are recommended. Hydrophobic or
hydrophilic PTFE membrane is offered to provide low extractables, low binding
and high recoveries. Purified samples are suitable for downstream analysis by
HPLC and LC/MS/MS. The plates also have a one-piece plate design for extended
incubations and are built with solvent-resistant membrane and plastics for
broad solvent compatibility.
Total Drug from Plasma by Acetonitrile Precipitation
Seven drugs were tested for percent recovery by acetonitrile plasma precipitation. Plasma stock samples (5 mL) were spiked with 3H labeled drug to a final 5 μM drug concentration followed by 1hour incubation. Protein was precipitated by the addition of acetonitrile (15 mL) and solution vortexed vigorously. An aliquot (300 μL) was added to each well using one plate per column per drug (n=8) and solution was then vacuum filtered (12“ Hg). Percent recovery was determined using an aliquot (100 μL) of filtrate versus an aliquot of the precipitated stock (cpm filtrate/cpm precipitated stock). Results show that both hydrophilic and hydrophobic MultiScreen Solvinert filter plates have >90% drug recovery.

