title: VersaCount: customizable manual tally software for cell counting.
abstract: BACKGROUND
  The manual counting of cells by microscopy is a commonly used technique across biological disciplines. Traditionally, hand tally counters have been used to track event counts. Although this method is adequate, there are a number of inefficiencies which arise when managing large numbers of samples or large sample sizes.
  
  
  RESULTS
  We describe software that mimics a traditional multi-register tally counter. Full customizability allows operation on any computer with minimal hardware requirements. The efficiency of counting large numbers of samples and/or large sample sizes is improved through the use of a "multi-count" register that allows single keystrokes to correspond to multiple events. Automatically updated multi-parameter values are implemented as user-specified equations, reducing errors and time required for manual calculations. The user interface was optimized for use with a touch screen and numeric keypad, eliminating the need for a full keyboard and mouse.
  
  
  CONCLUSIONS
  Our software provides an inexpensive, flexible, and productivity-enhancing alternative to manual hand tally counters.
authors.affiliation: Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA. joe@derisilab.ucsf.edu.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Kim
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Derisi