Abstract: Method for isolating biomass from an aqueous medium comprising cellular material comprising the steps of: 1) providing an aqueous medium comprising cellular materialalgae; followed by 2) subjecting the cellular materialalgae in said aqueous medium to lysis, whereby a lipid fraction comprising algal lipids and a solids fraction comprising algal solid material are formed, which fractions are dispersed in said aqueous medium; 3) separating at least part of said lipid fraction from the aqueous medium; 4) separating at least part of said solids fraction from the aqueous medium; wherein steps 3) and 4), and preferably also step 2), are performed in a single apparatus. The method is particularly suitable for isolating lipids from algae.