In situ stain for ADA activity of in vitro translation products. Arrow indicates position of human ADA. The dark bands at the bottom and top are rabbit hemoglobin and rabbit ADA, respectively, carried over from the reticulocyte translation reaction. The translation reactions were primed with the normal (wild-type) or mutant human ADA mRNAs (transcribed from cDNA); lane 1, wild-type control; lane 2, blank; lane 3, A215T (patient no. 2); lane 4, R101Q (patient no. 2); lane 5, P126Q (patient no. 1); lane 6, G216R (patient no. 1); lane 7, wild-type control.