Multicellular glandular secretory trichomes (GSTs) are the green factories of many plants. The expression of enzymes of secondary metabolism in GSTs has been shown for a number of species. In order to investigate the function of different cells of multicellular GSTs, a method based on the laser microdissection capture pressure catapulting technique has been developed for isolation of different cell types of the GST. Using a modified tissue preparation method, one outer pair of apical cells and two pairs of sub-apical, chloroplast containing cells, were isolated from GSTs of Artemisia annua. A. annua is the source of the widely used antimalarial drug artemisinin, an endoperoxide sesquiterpene lactone. The biosynthesis of artemisinin has been proposed to be located to the GSTs. The first committed steps in the conversion of farnesyl diphosphate to artemisinin is catalyzed by amorpha-4,11-diene synthase and a cytochrome P450 monooxygenase (CYP71AV1). First strand cDNA synthesised from RNA extracted from the different cell types was used as template in the PCR amplifications of these two transcripts. Our experiments showed expression of the two genes in the apical cells with no detectable amplification in the sub-apical cells. Elongation factor 1α was used as control and it was shown to be expressed in both cell types. We conclude that the two outer apical cells are the site for the initial steps of artemisinin biosynthesis while the two pairs of chloroplast-containing cells have other functions in the overall metabolism of glandular trichomes. Further studies on terpene metabolism in trichomes are in progress. The results of these extended studies will be discussed.