This paper examines whether PageRank algorithms are a valid instrument for the analysis of technical progress in specific technological fields by means of patent citation data. It provides evidence for patent data in biotechnology. Recent literature has been critical with regard to the use of PageRank for the analysis of scientific citation networks. The results reported in this paper indicate, however, that with some minor adaptations and careful interpretation of the results the algorithm can be used to capture some important stylised facts of technical progress and the importance of single patents relatively well especially if compared to indicators based on direct inward citations only.