Quantification of DNA-dependent RNA polymerase subunits and initiation factor(s) by antibody-linked polymerase assays

The antibody-linked polymerase assay is a method which allows one to assign RNA polymerase activity to SDS-denatured polypeptides on nitrocellulose membranes using antibodies which were raised against only partially purified polymerase preparations. Here we show that with this method not only enzyme subunits but also initiation factor(s) can be determined in crude homogenates. Moreover the determination is quantitative. Therefore changes in the amount of individual polymerase subunits and factor(s) can be visualized within different crude homogenates.