Research involving bacterial pathogens often requires enumeration of bacteria colonies. Here, we present a low‐cost, high‐throughput colony counting system consisting of colony counting software and a consumer‐grade digital camera or document scanner. We demonstrate that this software, called “NICE” (NIST's Integrated Colony Enumerator), can count bacterial colonies as part of a high‐throughput multiplexed opsonophagocytic killing assay used to characterize pneumococcal vaccine efficacy. The results obtained with NICE correlate well with the results obtained from manual counting, with a mean difference of less than 3%. NICE is also rapid; it can count colonies from multiple reaction wells within minutes and export the results to a spreadsheet for data processing. As this program is freely available from NIST, NICE should be helpful in bacteria colony enumeration required in many microbiological studies, and in standardizing colony counting methods. Published 2010 Wiley‐Liss, Inc.

Tissue-mimicking phantoms with well-defined wavelength-dependent absorption and scattering coefficients are essential for the development, calibration, and evaluation of optical medical devices designed to measure the broadband optical properties of tissues.^1,2 The absorption and scattering coefficients of biological tissues are proportional to the number of photons absorbed or scattered per centimeter of tissue traversed. These coefficients range over several orders of magnitude and are not necessarily correlated with each other, so robust methods to independently control and characterize the wavelength-dependent absorption and scattering coefficients of tissue-mimicking phantoms are crucial.¹

There is a need for a common reference point that will allow for the comparison of the optical properties of tissue-mimicking phantoms. After a brief review of the methods that have been used to measure the phantoms for a contextual backdrop to our approach, this paper reports on the establishment of a standardized double-integrating-sphere platform to measure absorption and reduced scattering coefficients of tissue-mimicking biomedical phantoms. The platform implements a user-friendly graphical user interface in which variations of experimental configurations and model-based analysis are implemented to compute the coefficients based on a modified inverse adding-doubling algorithm allowing a complete uncertainty evaluation. Repeatability and validation of the measurement results of solid phantoms are demonstrated for three samples of different thicknesses, $d=5.08mm$, 7.09 mm, and 9.92 mm, with an absolute error estimate of 4.0% to 5.0% for the absorption coefficient and 11% to 12% for the reduced scattering coefficient ($k=2$). The results are in accordance with those provided by the manufacturer. Measurements with different polarization angles of the incident light are also presented, and the resulting optical properties were determined to be equivalent within the estimated uncertainties.