During this period he worked on protein chemistry of RNA phages, but was beginning to shift his focus to animal cells and their viruses, and spent a sabbatical at Cold Spring Harbor Laboratory learning the associated techniques.

Together they produced the "Weber and Osborn" SDS-PAGE paper, which showed that proteins could be dissolved in sodium dodecyl sulfate (SDS), reliably separated by polyacrylamide gel electrophoresis (PAGE), visualized by Coomassie brilliant blue staining, and their molecular weights determined with reasonable accuracy.

[3] The pair moved to Germany in 1975 when Weber was offered the position of Director of the Department of Biochemistry and Cell Biology at the Max Planck Institute for Biophysical Chemistry in Göttingen.

He was a coauthor on a third fundamentally important research report showing that RNA interference could be routinely used to "knock down" the expression of major cellular proteins, work he performed with Thomas Tuschl and collaborators.

[5] This paper set the stage for the widespread use of RNA interference to turn off the expression of normal genes in mammalian systems, a centrally important cell biological technique.