Sample Requirements Overview

Prior to labeling, the quality of total RNA and genomic DNA samples will be checked with the Agilent 2100 Bioanalyzer (RNA) or by agarose gel (gDNA) and quantified with the NanoDrop ND-1000 UV-VIS spectrophotometer to measure A260/280 and A260/230 ratios.  Customers may submit bioanalyzer profiles or agarose gel images with samples to reduce costs. 

Generally,

• Agilent 2100 Bioanalyzer uses a RNA Integrity Number (RIN) to measure RNA sample quality. A RIN ≥ 8.0 indicates acceptable quality.

• Intact genomic DNA should appear as a compact, high-molecular weight band in an agarose gel, with no lower molecular weight smear. A small amount of degradation is not likely to interfere with direct DNA labeling. 

• The ratio between the readings at 260 nm and 280 nm provides an estimate of the purity of the nucleic acid. Pure preparations of RNA and DNA have OD ratio values (A260/A280) of between 1.8 and 2.0. Values below this indicate contamination of the sample with either phenol and/or protein. Values above this may indicate significant contamination of the sample with soluble carbohydrates.

• OD ratio values (A260/A230) less than 2.0 may indicate contamination by polysaccharides.

Samples with poor RNA or DNA quality will have QC costs billed to the customer and will only be processed after expressed direction of the customer with no guarantee of positive results.