On the determination of free L-tryptophan.
The determination of free L-tryptophan depends on several analytical well checked points e.g. absorbing effects, pH of the serum, dependence of the throughput, concentration dependence of retention, volume ultrafiltrated, cut-off, temperature dependence of the binding rate, purification on ion-exchange column, interfering substances of the fluorometric method. Ultrafiltration was compared to an ultracentrifugation technique. In normal human serum the concentration of free L-tryptophan is 3,1 +/- 0,6 microgram/ml and of the bound plus free form 12,2 +/- 1,12 microgram/ml. Both values are dependent on the albumin concentration.
D003101:Collodion; D003956:Dialysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013050:Spectrometry, Fluorescence / Q000379:methods; D014364:Tryptophan / Q000097:blood*; D014461:Ultracentrifugation
D014364:Tryptophan; D003101:Collodion