Inter-Individual Differences in RNA Levels in Human Peripheral Blood.

Area of Science:

• Biochemistry
• Molecular Biology
• Human Physiology

Background:

• Limited understanding of human blood RNA concentration ranges.
• Variability in RNA levels can affect molecular diagnostic accuracy.
• Previous studies have not comprehensively assessed inter-individual RNA differences in blood.

Purpose of the Study:

• To quantify peripheral blood total RNA levels in a healthy human cohort.
• To investigate inter-individual and intra-individual variability of blood RNA.
• To provide recommendations for interpreting gene expression studies in blood.

Main Methods:

• Collected peripheral blood samples from 35 healthy individuals (25 female, 10 male; aged 50-89).
• Quantified total RNA levels using spectrophotometry or similar methods.
• Performed repeated sampling on individuals to assess RNA level stability.

Main Results:

• Average total RNA level was 14.59 μg/ml of blood, with no significant sex difference.
• Individual RNA levels varied widely, from 6.7 to 22.7 μg/ml (3.4-fold range).
• Blood RNA levels were stable within individuals across repeated samplings.

Conclusions:

• Significant inter-individual differences in human blood RNA levels exist.
• These variations necessitate consideration in quantitative RT-PCR and RNA sequencing studies.
• Accurate interpretation of blood gene expression requires assessing mRNA per unit of total RNA and per unit of blood.