Small-column chromatofocusing of cerebrospinal fluid and serum immunoglobulin G

Chromatofocusing performed by the Pharmacia fast protein liquid chromatographic system equipped with a specially designed small column was applied for examinations of submilligram quantities of cerebrospinal fluid and serum immunoglobulin G. The separations were based on a pH gradient between 9.5 and 6.0. Mono- or oligoclonal immunoglobulin G components having pI values within the optimal working range of the gradient were easily identified and the findings differed clearly from those of normal immunoglobulin G. The capacity to detect abnormal immunoglobulin G components compared well with previous experiences from the commercially available Mono P column. The small column offers advantages by having a shorter separation time, a decreased dilution of sample in the eluate and a lower consumption of start and eluent buffers.