Immunological quantitation of chloroplast ferredoxin.

An immunosassy for the quantitative determinations of ferredoxins in cell free extracts from plant tissues is described. The method is accurate for the assay of 0.3-1.5 nmol ferredoxin directly from the extracts. The following average values (nmol ferredoxin/mg extractable protein) were obtained: 3.9, 1.8. 5.90, 14.8 and 10.9 for Euglena gracilis, spinach, parsley, lettuce, and broccoli, respectively. Specific factors affecting the method are discussed in detail.