The present invention provides improved methods for labeling nucleotides. The method of the invention for labeling nucleotides comprises the steps of: reacting a reactive moiety of a linker, which linker is a platinum compound having a stabilizing bridge and two reactive moieties, with an electron donating moiety of a spacer, which spacer comprises a chain having at least four atoms and at least one heteroatom in the chain, which spacer further comprises said electron donating moiety at one end of the chain and a reactive moiety at the other end of the chain; reacting the reactive moiety of said spacer with a label; reacting the other reactive moiety of said linker with a nucleotide. A major advantage of the invention is that all nucleotides can be labeled by the method of the invention, whereas until now the attachment of a label was mostly restricted to one or certain nucleotides.