 Other methods for elucidating the cellular location of proteins requires the use of known compartmental markers for regions such as the ER , the Golgi , lysosomes or vacuoles , mitochondria , chloroplasts , plasma membrane , etc . With the use of fluorescently tagged versions of these markers or of antibodies to known markers , it becomes much simpler to identify the localization of a protein of interest . For example , indirect immunofluorescence will allow for fluorescence colocalization and demonstration of location . Fluorescent dyes are used to label cellular compartments for a similar purpose . 
