By incorporating thiols into the sugars that project from cell surfaces, the adhesion properties of the cells can be altered. Kevin J. Yarema and coworkers at Johns Hopkins University have harnessed the sialic acid biosynthetic pathway to put thiol analogs of (shown) N-acetyl-D-mannosamine in oligosaccharides on the surface of human Jurkat cells, a type of lymphoma cell (Nat. Chem. Biol., published online Feb. 12, dx.doi.org/10.1038/nchembio770). After the cells were treated with a reducing agent to eliminate disulfide bonds, the number of thiols on the surface increased by about 120-fold, compared with that on cells not fed the analog. The Jurkat cells, which are normally nonadhesive, self-assembled into clusters and could be attached to maleimide-functionalized glass surfaces. The sugars with thiol analogs could be used in tissue engineering as a way to attach cells to scaffolds.