pubmed-article:4056406 | pubmed:abstractText | Spun columns were used to separate IgM from serum samples by exploiting molecular weight and size difference between IgM and other serum antibodies. Miniature gel chromatography columns were prepared in 3 ml syringe barrels. A polyacrylamide liquid chromatography gel, Bio-Gel P-200, was chosen to exclude proteins with molecular weights greater than 200,000. IgM, 900,000 MW, was excluded while IgG, 150,000 MW, was retained in the gel column. Centrifugation of the serum-loaded columns in test tubes accomplished the separation in one step by eluting a void volume equal to the sample volume from each column into a holding tube. IgM recovery in the eluent exceeded 96% of the total serum IgM in the pre-column sample. No IgG was detected in the eluent. IgM separated from La Crosse encephalitis immune human serum retained immunological activity in a viral neutralization test. Spun column chromatography is eminently suitable for diagnostic laboratories as more than 100 sera may be fractionated in one day using inexpensive materials and a low-speed centrifuge equipped with a swinging-bucket rotor. | lld:pubmed |