MICROBExpress (patent pending) is currently the only commercially available bacterial mRNA purification kit. It uses a novel strategy that rapidly removes >95% of the 16S and 23S rRNA from total RNA of E. coli and other bacterial species (Figure 1). MICROBExpress can be used with total RNA obtained by a variety of methods, including glass fiber filter-based methods (such as Ambion's RNAqueous Kits), and phenol-based methods (such as Ambion's RiboPure-Bacteria Kit). The mRNA isolated with MICROBExpress is a superior template for synthesizing labeled cDNA for array analysis and is ideal for quantitative RT-PCR, Northern applications, and cDNA library construction.
Quick and Specific Removal of rRNA
In the first step of the MICROBExpress procedure, total RNA is mixed with an optimized set of capture oligonucleotides that bind to bacterial 16S and 23S rRNAs. Next, the rRNA hybrids are removed from the solution using derivatized magnetic microbeads. The mRNA remains in the supernatant and is recovered by ethanol precipitation. In addition to purifying bacterial mRNA that is virtually free of 16S and 23S rRNA, this method also delivers the benefits of quick processing (less than 2 hours), ease of handling, and scalability.
Figure 1. Depletion of Bacterial 16S and 23S rRNA with MICROBExpress. 16S and 23S rRNAs were selectively removed from a 10 g E. coli total RNA sample using the MICROBExpress Kit. A second 10 g sample of the same total RNA prep was subjected to a mock MICROBExpress procedure without the Capture Oligo Mix (total RNA). The electropherograms above were generated by running each RNA sample on an Agilent 2100 bioanalyzer using the RNA LabChip. Aligning the traces reveals >95% removal of the 16S and 23S rRNA peaks in the mRNA purified with the MICROBExpress Kit. (Note that the peak corresponding to 5S rRNA and tRNAs is not affected by the MICROBExpress procedure.)
Using total RNA that lacks small RNA molecules (tRNA and 5S rRNA) as the starting material, the MICROBExpress procedure produces the highest possible level of mRNA enrichment. Small RNAs can be removed during total RNA isolation by using our RiboPure Bacteria Kit. Alternatively, small RNAs can be removed from existing total RNA samples using Ambion's MEGAclear Kit.
You can also view a list of organisms that are compatible with the MICROBExpress Kit.
To extend the kit's compatibility with other microbes, Ambion now offers a MICROBExpress Module for Cyanobacteria mRNA isolation as well as MICROBExpress Modules for Pseudomonas, Campylobacter, Helicobacter, and Rhodobacter mRNA isolation.
Cat# Product Name Size 1905 MICROBExpress Bacterial mRNA Enrichment Kit 20 rxns 1925 RiboPure-Bacteria Kit 50 purifications 5750 MICROBExpress Module: Pseudomonas 20 purifications 5751 MICROBExpress Module: Campylobacter/Helicobacter 20 purifications 5752 MICROBExpress Module: Rhodobacter 20 purifications 5753 MICROBExpress Module: Cyanobacteria 20 purifications