Recent Decisions

ACT OF STATE--Act of State Doctrine Not a Bar to Adjudication of a Counterclaim Robert M. Erickson ========================== ADMIRALTY--Ship Mortgage Act of 1920--Deficiency Judgment against Mortgagor in Personam Not Precluded by State Law when Vessels were Sold at Public Foreclosure Auction without Prior Appraisal Jack F. Stringham, II =========================== ALIENS--Immigration and Naturalization--Restriction of Commuter Aliens\u27 Access to Domestic Employment by Attorney General is Abuse of Discretion Alan Marchisotto ================= EXTRADITION--Principle of Specialty--Specialty does not Preclude Prosecution for Similar Offense when Asylum Nation Would Not Consider it a Breach of Faith Attorney General of the United States, 462 F.2d 475 (2d Cir. 1972),petition for cert. filed, 41 U.S.L.W. 3114 (U.S. Aug. 26, 1972) (No.332). James T. Campbell ========================= JURISDICTION--Forum Selection Clauses--United States Courts will Enforce Forum Selection Clauses in International Towage Contracts Absent Exceptional Circumstances Ralph C. Oser ======================== TAXATION--Foreign Tax Credit--Foreign Income Tax Credit Under Section 901 Allowable Only for Taxes Imposed on Net Gain or Profit David A. Boillo

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data