faq_ngs_11.md

+**How to measure RNA quality and quantity?**  
+**RNA/DNA purity**  
+The ratio of absorbance 260/280nm  is used to assess the purity of DNA and RNA.  
+A ratio of ~1.8 is generally accepted as “pure” for DNA; a ratio of ~2.0 is generally accepted as “pure” for RNA. Lower ratio may indicate the presence of protein, phenol or other contaminants that absorb strongly at or near 280 nm.  
+The ratio of absorbance 260/230 nm for “pure” nucleic acid are often in the range of 2.0-2.2. If the ratio is appreciably lower than
+expected, it may indicate the presence of contaminants (EDTA, carbohydrates, phenol,TRIzol reagent,...)  
+
+**RNA quality**  
+RIN score /DIV    
+[**evaluating-rna**](https://www.illumina.com/content/dam/illumina-marketing/documents/products/technotes/evaluating-rna-quality-from-ffpe-samples-technical-note-470-2014-001.pdf)  
+![image](uploads/b32c3d9e4039a3d32873397ee84a76da/image.png)
+