Fig. 3. Colocalization experiments of RyR3 with endoplasmic reticulum markers. RyR3-expressing cells were decorated with polyclonal antibodies against calreticulin or Ins(1,4,5)P₃R1 and with monoclonal antibodies angainst SERCA pump. Calreticulin was detected by a FITC conjugated anti-goat antibody. Ins(1,4,5)P₃R1 was detected by an Alexa-conjugated anti-rabbit antibody. SERCA pump was detected by a Cy₃-conjugated anti-mouse antibody. The Golgi apparatus was stained by transfecting the RyR3-expressing cells with the cDNA for a Green Fluorescent Protein containing a Golgi targeting signal. Cells were counterstained with monoclonal antibodies against RyR3 and TRITC-, Cy₃- or Alexa-conjugated anti-mouse secondary antibodies. Panels show representative sections from top to bottom of the cells at about 1 µm intervals.