Abnormal behavior of polyamines on gel filtration: a cautionary note

The polyamines, spermine and spermidine, have been shown to persist in various tissue extracts despite procedures such as dialysis and ultrafiltration which normally remove such low molecular weight compounds. We have found that polyamines in tissue extracts and the standard compounds alone can migrate as much higher molecular weight compounds on gel filtration under a variety of conditions. Thus, even relatively pure fractions obtained from tissue extracts may be contaminated with, or consist entirely of, polyamines, which are potent inhibitors of cell proliferation under certain conditions.