 The study of proteins in vivo is often concerned with the synthesis and localization of the protein within the cell . Although many intracellular proteins are synthesized in the cytoplasm and membrane @-@ bound or secreted proteins in the endoplasmic reticulum , the specifics of how proteins are targeted to specific organelles or cellular structures is often unclear . A useful technique for assessing cellular localization uses genetic engineering to express in a cell a fusion protein or chimera consisting of the natural protein of interest linked to a " reporter " such as green fluorescent protein ( GFP ) . The fused protein 's position within the cell can be cleanly and efficiently visualized using microscopy , as shown in the figure opposite . 
 The study of proteins in vivo <a href='drop_aux' title='1'><mark>is</mark></a>often concerned with the synthesis and localization of the protein within the cell . Although many intracellular proteins are synthesized in the cytoplasm and membrane @-@ bound or secreted proteins in the endoplasmic reticulum , the specifics of how proteins are targeted to specific organelles or cellular structures <a href='drop_aux' title='2'><mark>is</mark></a>often unclear . A useful technique for assessing cellular localization <a href='uninflect' title='3'><mark>uses</mark></a> genetic engineering to express in a cell a fusion protein or chimera consisting of the natural protein of interest linked to a " reporter " such as green fluorescent protein ( GFP ) . The fused protein <a href='null_genetive' title='4'><mark>'s</mark></a>position within the cell can be cleanly and efficiently visualized using microscopy , as shown in the figure opposite . 
The study of proteins in vivo often concerned with da synthesis and localization of the protein within tdacell . Although many intracellular proteins r synthesized in the cytoplasm and membrane @-@ bound or secreted proteins in the endoplasmic reticulum , thdapecifics of how proteins arrargeted to specific organelles or cellular structures often unclear . A useful technique for assessing cellular localization use genetic engineering to express in a cell a fusion protein or chimera consisting of thedatural protein of interest linked to a " reporter " such as green fluorescent protein ( GFP ) . The daed protein  position within the cell can be cleanly and efficiently visualized using microscopy , as shown in the fdare opposite .