Twelve enzymes from mature pollen grains of maize were separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The separation in the second dimension was both in the presence and absence of sodium dodecyl sulfate (SDS). Ten of the investigated enzymes lost activity after separation in the presence of SDS, but those of esterases and acid phosphatase could be recovered. On the other hand, 2-D electrophoresis without SDS is suitable for the analysis of maize pollen pectinesterase, malate dehydrogenase, glutamic-oxalacetic transaminase, diaphorase, superoxide dismutase, and phosphoglucose isomerase. 1-D PAGE and isoelectric focusing (IEF) are sufficient to analyze glucose-6-phosphate dehydrogenase, alcohol dehydrogenase, shikimic dehydrogenase, and glutamate dehydrogenase. The possibility of applying 2-D electrophoresis for the analysis of enzymes from single stigma and stigma exudate is dicussed.