Quantitative visualization of intracellular lipids concentration in a microalgae cell based on Raman micro-spectroscopy coupled with chemometrics

•Lipids and biomass in microalgae were significant affected by nitrogen stress.•A multivariate linear regression model for determination of lipids was established.•Quantitative visualization of intracellular lipids in microalgae cell was realized.•Characteristic Raman bands for quantitative determination of lipids were extracted.•Spatial and temporal dynamic characteristics of intracellular lipids were illustrated.