Indirect Immunofluorescence Assay in Chlamydomonas reinhardtii

Abstract

Determining the protein localization is essential to elucidate its in vivo function. Fluorescence-tagged proteins are widely used for it, but it is sometimes difficult to express tagged proteins in Chlamydomonas. Alternatively, indirect immunofluorescence assay is also one of the widely used methods and many reports determining the localization of Chlamydomonas proteins using this method are published. Here, we introduce a protocol of indirect immunofluorescence assay adapted from our papers reporting LCIB (CO₂-recycling factor in the vicinity of pyrenoid; Yamano et al., 2010), LCI1 (plasma membrane-localized inorganic carbon transporter; Ohnishi et al., 2010), HLA3 (plasma membrane-localized ABC-type bicarbonate transporter; Yamano et al., 2015), and LCIA (chloroplast envelope anion channel; Yamano et al., 2015) in Chlamydomonas reinhardtii. The protocol described here could be useful for observing the protein of interest in other algae cells.