Interference of zwitterionic biological buffers with the Lowry method of protein determination

Abstract

Folin and Ciocalteu's phenol reagent may be reduced by a variety of compounds, which therefore interfere with the Lowry method of protein determination (1,2). Peters and Fouts (3) reported that two of the zwitterionic biological buffers described by Good et al. (4) reacted strongly with the Folin reagent and thus seriously interfered with protein determinations. The zwitterionic buffers have many properties which lead to their use in biological work, where protein estimations will be required. Since the publication of Good et al. (4), the range of zwitterionic buffers has been increased. The possibility that these other buffers may also produce artefacts has therefore been investigated.