Sol-gel derived monolithic silica columns containing entrapped
dihydrofolate reductase were used for frontal affinity chromatography of
small molecule mixtures. The output from the column combined with a
second stream containing the matrix molecule (HCCA) and was directly
deposited onto a conventional MALDI plate that moved relative to the
column via a computer controlled x-y stage, creating a semi-permanent
record of the FAC run. The use of MALDI MS allowed for a decoupling of
the FAC and MS methods allowing significantly higher ionic strength
buffers to be used for FAC studies, which allowed for better retention of
protein activity over multiple runs.