mRNA quantitation by a simple and sensitive RNAse protection assay

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Accurate quantification of mRNA levels is crucial for understanding gene expression.
• Existing methods may lack the precision required for detailed cellular and tissue analysis.
• A need exists for a reliable assay to measure specific mRNA populations.

Purpose of the Study:

• To develop and validate a highly precise RNAse protection assay for mRNA quantification.
• To establish a method for measuring apolipoprotein (apo)-A-I, apo-B, and apo-E mRNA levels in non-human primate tissues.
• To demonstrate the utility of an internal standard for enhancing assay accuracy.

Main Methods:

• Utilized RNAse protection assay with a synthesized internal RNA standard.
• Constructed RNA quantitation vectors (pRQV) for generating sense (internal standard) and antisense (probe) RNA strands.
• Performed solution hybridization, RNAse digestion, and gel electrophoresis to separate and quantify RNA fragments.
• Calculated authentic mRNA mass based on radioactivity ratios of protected fragments.

Main Results:

• The developed assay significantly increased the precision of mRNA level measurements.
• Successfully quantified apo-A-I, apo-B, and apo-E mRNA in cynomolgus monkey tissues.
• Demonstrated that distinct fragment sizes of internal standard and authentic mRNA-probe hybrids allow for accurate differentiation and quantification.

Conclusions:

• The RNAse protection assay with an internal standard provides a precise and versatile method for mRNA quantification.
• This technique is applicable to any mRNA for which corresponding cDNA is available.
• The assay is valuable for studying gene expression patterns in various biological contexts, including non-human primate models.