mRNA extraction from Gram positive bacteria

[James Graham]

I think you will find a oscillating or high-speed reciprocating 
shaker almost essential for efficient isolation from many gram 
positives. These devices shake the pelleted suspention at high 
speeds (6K rpm) with zirconimum fragments (beads) and will increase 
the total RNA yield from say Mycobacterium almost 10X compared to 
other grinding and lysis procedures, in my experience. Two such 
devices are "Fast-prep" from Gibco and "Mini Bead Beater".

As for Trizol, its just colored buffered phenol of low PH, with a 
buffer system that supposedly allows recovery of the DNA from the 
organic phase. Published reports show that up to 20% of the nucleic
acids recovered from the aqueous phase may be DNA.

See Fischetti's recent Analytical Biochemisty article for details.

Jim
J. Graham
Biology Department