LAUSR

We propose a new high-throughput ultrafast method for large scale proteomics approaches by speeding the classic filter aided sample preparation protocol, FASP, from overnight to a 2.5 h. Thirty-six samples can be treated in 2.5 hours, and the meth-od is scalable to 96-well plate-based pipelines. After a modification of the FASP-tube, the steps of protein reduction, protein alkylation, and protein digestion of complex proteomes are done in just 5.25 min each one under the effects of an ultrasonic field (7 cycles: 30s on and 15s off). The new method was compared with the standard overnight digestion FASP protocol, and no statistical differences were found for more than 92.4%, 92%, and 93,3% of the proteins identified studying the prote-ome of E. coli, mouse brain, and mouse liver tissue samples. Furthermore, the successful relative label-free quantification of four spiked proteins in E. coli samples, namely BSA, β-lactoglobulin, α-casein, and α-lactalbumin, was achieved, either using the ultrasonic-based FASP protocol or the classic overnight one. The new US-FASP method matches the analytical minimalism roles as time, cost, sample requirement, reagent consumption, energy requirements and production of waste products are reduced to a minimum while maintaining high sample throughput in a robust manner as all the advantages of the filter aided sample preparation protocol are maintained.