Qiaexcel advanced capillary electrophoresis instrument

Staged young adult tau transgenic C. elegans were grown from eggs at 20 °C for 3 days on 5XPEP plates, washed off plates in M9 buffer, and collected by centrifugation. RNA was extracted from ~100 μL of packed worms per sample using Tri-Reagent (Molecular Research Center) as per manufacturer instructions. Poly(A) tail lengths were assayed using the USB Poly(A) Tail-Length Assay Kit (Affymetrix) as per manufacturer instructions with the following modification to the PCR amplification step. The PCR reaction consisted of 10 μL of HotStart Taq, 7 μL of nuclease-free water, 0.5 μL of 10 μM gene-specific primer (see below), 0.5 μL of 10 μM Universal PCR Reverse Primer, and 2 μL of the diluted reverse transcription sample. A three-step PCR reaction with 40 cycles of amplification was used to amplify the signal. PCR products were run on a QIAexcel Advanced capillary electrophoresis instrument (Qiagen) using a QIAxcel DNA high resolution Kit with QX DNA Size Marker pUC18/HaeIII (catalog #929550) at 20 ng/uL and QX alignment marker 15 bp/600 bp (catalog #929530). Samples were processed using the 0M400 method with a 20 s sample injection time and analyzed with the QIAxcel ScreenGel Software for major peak, median signal, and concentration.