Correction: Micro-Raman Spectroscopy of Silver Nanoparticle Induced Stress on Optically-Trapped Stem Cells. - Aseefhali Bankapur; R. Sagar Krishnamurthy; Elsa Zachariah; Chidangil Santhosh; Basavaraj Chougule; Bhavishna Praveen; Manna Valiathan; Deepak Mathur (PLoS ONE, 2012)