Protection by albumin against non-specific binding of SLPI to plastic. The diagram shows the concentration of SLPI in SFM added to tissue culture plates without cells, before addition of NE or control (baseline) and 10 min afterwards. Parallel wells used SFM containing human serum albumin at 1 mg/ml. Data shown are the mean results from 3 experiments with SEM represented by the error bars. Without albumin, almost all the SLPI was lost regardless of whether NE was added. Albumin provided partial protection against loss of SLPI at baseline and after addition of NE.