Fig. 2.

Fluorograph of two-dimensional electrophoretic separation of proteins from 20 one-cell fertilised mouse ova injected with mouse globin mRNA and incubated in ³H-labelled amino acids. Isoelectric focusing (IEF) was from left (pH 7.5) to right (pH 4.5) and SDS-polyacrylamide electrophoresis was from top to bottom. The technique used was basically that of O’Farrell, as previously described^12,16. The IEF was carried out with pH 3–10 ampholines. Marker proteins on the right margin are lactoglobulin (top, MW = 18,400) and methaemoglobin (bottom, MW= 16,000). The two radioactive spots indicated by the arrows coincide with the position of the non-radioactive globin marker protein prepared from mouse blood. α and β indicate the positions of α- and β-chains of globin.