1. A method of using Raman imaging microscopy for evaluating drug action within living cells comprising the steps of: first measuring a Raman spectrum of said drug to determine a pretreatment fingerprint of said drug; second measuring a Raman spectrum of said living cells in order to determine a pretreatment fingerprint of said living cells; treating a culture of said living cells with said drug to obtain treated living cells; next measuring a Raman spectrum of said treated living cells to obtain post-treatment images of said living cells; processing said post-treatment images and pretreatment fingerprints to obtain processed post-treatment images and processed pretreatment fingerprints; and dividing said post-treatment images by said processed pretreatment fingerprints to obtain a ratio of images which indicate the changes of said living cells after said treating whereby said changes are used to determine said drug action.