Ambion® Millennium™ Marker-Formamide is designed to determine the size of single-stranded RNA transcripts from 0.5 to 9 kb. Can be used with any Northern blot hybridization protocol. Sufficient markers are provided for 25 Northern blot hybridization gel lanes. They consist of a mixture of 10 different RNA transcripts with easy-to-remember sizes: 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6 and 9 kilobases. This marker is provided in the formamide form, which provides greater stability and RNase resistance compared to other high molecular weight RNA markers. They can be stained with ethidium bromide during or after electrophoresis. Due to their uniform number and spacing, these markers are ideal for constructing accurate standard curves and determining mRNA size. They also provide a reference scale that allows easy verification and comparison of known bands. Using ethidium bromide staining, 1-2 μg (1-2 μl) of RNA Millennium™ marker produces 10 distinct bands on a 1% denaturing agarose gel. All marker lots undergo stringent nuclease testing and are stable overnight at 37°C.