Three transfer factors were prepared from pig,human and bovine spleens by homogenization and dialysis. Under the same conditions, the physicochemical properties of these 3 TFs were determined by means of determination of nucleo-tide and peptide contents, HPRC, analysis of free a mi no acids, absorbance, etc.HTF and PTF absorbance of E 260/E280 was more than 2, the strongest absorption spectrum for HTF and PTF was at a wave length of 250 ±2 nm,and these two TFs were separated into 1 -2 distinct fractions by ...