Analyses of B29 and mb-1 mRNA expression in B-CLL cell samples using simultaneous RPA. Antisense riboprobes were hybridized with total cellular RNA samples from B-CLL cells samples (20 μg/lane) and from control Ramos B cells (5, 10, and 20 μg/lane), RNAse-digested, and analyzed in gels. RNAse protected probe fragments corresponding to the majority of the B29 mRNA coding sequence (900 bp), the multiple 5′ B29 mRNA termini (110 to 135 bp), and an internal mb-1 coding region segment (90 bp) are displayed for 14 representative B-CLL cell samples and the Ramos controls.