Skin is very fibrous and elastic, and efficient RNA extraction from this tissue can be very difficult. We have previously tested several homogenizers to homogenize dog skin samples, with unsatisfactory results, including poor homogenization, poor RNA yield and warming of the samples. To find a better option for RNA extraction from dog skin samples, several types of beads were tested for efficacy in homogenizing frozen skin biopsies using a Precellys® 24 bead homogenizer.
Dicing the tissue prior to homogenization was essential as whole 4mm biopsies didn’t homogenize well.
There did not appear to be a linear relationship between RNA concentration and bead size or density. It is likely the variation in RNA concentration observed is mostly due to variation in how finely diced the tissue was before homogenization.
Trizol has previously been observed to turn black in combination with steel beads. This didn’t occur here, possibly because the sample didn’t get warm during homogenization.
Table 1. RNA concentrations and purity observed using different lysing kits.