Dear Henriette: We have been using the BioCAD fairly extensively for the
purifcation of synthetic peptides. It is very versatile and reproducible.
The Poros R-2 column works well if there are not too many <5 contaminants
in the peptide mix and if the peptide is almost 70 % or more pure. In
purifying peptides where the target is less than 40 %, I hook up semi-prep
or prep HPLC column and obtain excellent resolution. Another decided
advantage is the Advantec Fraction collector, once programmed it is very
reliable. We have used programs written over 2 years ago to purify new
batches of synthetic peptides with excellent recoveries. The BioCAD also
operates the HPLC columns at significantly less backpressures than an HPLC
system. On the other hand, our success with it for purifying small amounts
of proteins have not been stellar. The POros columns are good for some,
but (large particles) generally do not display the same level of resoultion
one gets with standard FPLC or HPLC columns. However, the reproducibility
of the gradient with the BioCAD is sometimes very useful, provided you can
lose a certain fraction of the protein. On the whole a great machine for
purifying larger amounts of biomolecules, ease of use, upkeep and
reproducibility. Downside, the POros resins lack the level of resolution
observed with traditional FPLC/HPLC packings, but can compensate with
higher throughput. In any event, this is a good machine to have if you can
afford it. The parts such as lamps etc are quite expensive and their
service contracts are a bit high, and no doubt will be higher now that it
is part of the PE superstructure. I forgot to add: A good machine to train
people on several aspects of protein/peptide separations. I will be happy
to send you some of our results with the BioCAD if you want them, Gautam
Gautam Sarath
N-226, Beadle center
Protein Core Facility
Department of Biochemistry
University of Nebraska-Lincoln
Lincoln, NE 68588-0664
Phone: 402-472-2928
FAX: 402-472-7842