The present invention provides a method of sequencing a single polynucleotide in which the nucleotide base and/or probe which is incorporated during sequencing is labelled with a bead which is detected to identity the base and/or probe which has bound to the single polynucleotide. Particularly, the detection of the bead may be carried out using an apparatus comprising a surface provided with a means for detecting a bead e.g. with one or more light sensitive elements.