We extract total proteins from tough, recalcitrant marine phytoplankton for quantitative analyses of protein composition. We are seeking means to increase the throughput and reliability of our extractions. In this experiment, we compare our standard microprobe sonication/flash freeze protocol to extract total proteins from a single sample at a time, to the Precellys beadbased system to extract total proteins from multiple samples in parallel.
The total yield of proteins extracted from each species was similar using the sonication/flash freeze protocol or the Precellys® bead beating systems (Table 1). Simultaneous, parallel extractions with the Precellys® system mean sample throughput and reproducibility are higher than with our sonication/flash freeze protocol. The immunoblots show that the quality of the protein extractions was comparable for both a large, soluble protein (ribulose-1,5-bisphosphate carboxylase oxygenase; Figure 1) and for a highly hydrophobic membrane protein (PsbA, D1) (not shown).
Figure 1: Comparison of ribulose-1,5-bisphosphate carboxylase oxygenase (RbcL) immunodetection from phytoplankton after protein extraction through sonication or
Precellys bead beating. RbcL was detected by Immunoblotting using a chicken anti-RbcL primary antibody and a horseradish peroxidase-conjugated goat anti-chicken secondary antibody. MW, molecular weight protein ladder (in kDa).