AbstractProcedures developed for the fractionation and sub‐fractionation of proteins in whole egg have been applied to separated white and yolk samples and to whole egg reconstituted from them. The fractionation pattern of whole egg soluble proteins on diethylaminoethylcellulose differed from a simple combination of the corresponding patterns for white and yolk soluble proteins. All the fractions and sub‐fractions were dialysed and freeze‐dried for analysis.The main effect of mixing yolk with white appears to be the conversion of some insoluble lipoproteins to a soluble form, the bulk of which has no affinity for diethylaminoethylcellulose but can be separated by chromatography on car‐boxymethylcellulose into a number of fractions that have high lipid contents and are clearly derived from the low density fraction of yolk.