spectrophotometer (IMAGE) Penn State Caption A Penn State student measures modified RNA concentration with a spectrophotometer. The researchers found that modified RNA improves the efficiency of CRISPR-Cas9 delivery. Credit Kate Myers/Penn State Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.