Users rely on advice and recommendations as well as instruction by core facility staff in the design, execution, and interpretation of their experiments. While education is arguably one of the most important core facility functions, it is seldom included in the cost recovery calculations that form the basis for developing service charge rates. Obviously, this comparison suggests that in toto all of these latter expenses, which can be extremely difficult to estimate prospectively, actually contribute most of the cost of the analysis. Since this subsidy most often comes in the form of salary support, it is generally not easy for a user to make an accurate comparison of service charges assessed in different facilities. For instance, a facility that specializes in extended sequencing runs carried out in the low picomole range would incur considerably higher costs in terms of optimizing instrument performance than a facility whose task it was to routinely screen batches of a recombinant protein by sequencing the first five residues at the nanomole level.
Peptide synthesis provides an excellent illustration of potential differences in extent of service.
Service charges should therefore be considered to represent an important but certainly not the only source of revenue for core facilities.