This document specifies a method for the detection and identification of microalgae, macroalgae (seaweed), cyanobacteria and Labyrinthulomycetes by using morphological methods and/or molecular methods. The morphological methods in this document are applicable to harvested wet biomass and to harvested dried unground biomass from microalgae, macroalgae, cyanobacteria and Labyrinthulomycetes that have been grown and/or harvested for further processing and/or use. The molecular methods in this document are applicable to harvested wet biomass and to harvested dried and/or ground biomass from microalgae, macroalgae, cyanobacteria and Labyrinthulomycetes that have been grown and/or harvested for further processing and/or use. This document describes a toolbox, consisting of several identification methods that can be chosen according to the applicability and purpose of the identification: morphological methods based on observation and referring to scientific literature on taxonomy: macroscopic observation; light microscopic observation; molecular methods of sequencing and blasting of sequences: 16S-rDNA sequencing; 18S-rDNA sequencing; rbcL DNA sequencing; ITS sequencing; COX 1 gene sequencing; tufA gene sequencing. This document does not deal with genetic purity of the biomass or quantification of the identified taxa.-