In a direct ELISA performed in lab,  the [item1] is alread…

  In a direct ELISA performed in lab,  the is already adsorbed to the bottom of the wells before the experiment begins.  In the next step, is added to each well followed by triple wash . In the next step, is added to attach to the potentially present antibody from patient fluid.  In the last step, is added and a color change will occur in a positive sample.