S trap mini devices

LB broth and LB agar were from Amresco (Solon, OH). Urea was from Teknova (Hollister, CA). LC-MS pure reagents (water, ethanol, acetonitrile, and methanol) were purchased from J.T. Baker (Radnor, PA). Gel-electrophoresis reagents were from Bio-Rad (Berkley, CA). Iodoacetamide (IAA) was purchased from MP Biomedicals (Solon. OH). All other reagents are from Sigma-Aldrich (St. Louis, MO) unless specified. The gels used for electrophoresis were from Genscript Biotech Corporation (Piscataway, NJ). Separation occurred on a Mighty Small II from Hoefer Inc. (Holliston, MA) and gels were imaged with a Bio-Rad Gel-Doc EZ Imager. DNA Miniprep spin filters were purchased from Bioneer Corporation (Oakland, CA) and the S-Trap mini devices were from Protifi (Huntington, NY). At the time of publication 200 Miniprep columns from Bioneer have a US price of $115 including DNA reagents and bulk miniprep columns from Epoch Life Science (http://www.epochlifescience.com/) can be obtained for $0.42 each without reagents. Hydrophilic–lipophilic balance (HLB) solid phase extraction (SPE) cartridges (10 mg) from Waters (Milford, MA) were used to desalt peptide samples prior to analysis on a Q-Exactive HF from Thermo Fisher Scientific (San Jose, CA) or an ultrafleXtreme MALDI-TOF from Bruker Scientific LLC (Billerica, MA).