This article takes the inquiry into semiotic repertoires beyond their classifications and inventories to analyse their interactions with each other and the way they gain indexicality in situated communication. As previous theorisation suggests that semiotic repertoires are deployed by agentive individuals, this article draws from New Materialism to focus on how social agents, semiotic repertoires, and material ecologies work together in distributed practice for meaning making. Expanding sociolinguistic constructs for this purpose, the article defines the relevant units and objects of analysis, and illustrates the framing of activities in indexing the values, meanings, and relationships of semiotic repertoires. The role of these repertoires in the interaction of an international community of scientists is analysed through the research group meeting of a team of microbiologists. The article demonstrates that though the focal participant from Korea claims limited English grammatical proficiency in his personal repertoire, he draws strategically from the repertoires in the physical setting and those of his disciplinary community to communicate successfully.