[2] Kresge, Simoni and Hill[5] have presented a general appreciation of Cleland's life and career.

[6][7][8] Building on this work he made kinetic studies of various enzymes, including isotope exchange of creatine kinase.

[9] Cleland was a pioneer in the use of computers to analyze enzyme kinetic data,[10] and his Fortran programs that implement Wilkinson's analysis,[11] which he distributed to anyone who requested them, were very influential.

In the latter part of his career Cleland contributed greatly to studies of the use of kinetic isotope effects as a tool for elucidating mechanisms of enzyme catalysis.

[12] He was the first to use dithiothreitol for the reduction of disulfide bonds in proteins, and the compound is accordingly often called Cleland's reagent.