Agarose gel electrophoresis of RT-PCR products stained with ethidium bromide.

(L) DNA ladder. (1) Bone marrow mononuclear cell mRNA with enolase primers showing an expected product of 329 bp. (2) mRNA from IL-2–activated NK cells with enolase primers. (3) Positive control of a 400-bp sequence of human SDF1a amplified with SDF1a primers. (4) mRNA from IL-2–activated NK cells with SDF1a primers showing an absence of SDF1a message. (5) Negative control, mRNA from IL-2–activated NK cells, reverse transcriptase was omitted. (6) Negative control, mRNA from activated NK cells was omitted. (7) Negative control, mRNA from activated NK cells, Taq polymerase omitted.