Published-Ahead-of-Print December 5, 2005, DOI:10.2164/jandrol.05112
Journal of Andrology, Vol. 27, No. 2, March/April 2006
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.05112
The Precision and Accuracy of Six Different Methods to Determine Sperm Concentration
NILENDRAN S. PRATHALINGAM*,
,
WILLIAM W. HOLT
,
STUART G. REVELL
,
SIAN JONES
AND
PAUL F. WATSON*,
From the * Royal Veterinary College, Camden Town,
London, United Kingdom; the
Institute of
Zoology, Regent's Park, London, United Kingdom; and the
Genus Breeding Ltd Ruthin, Denbighshire,
United Kingdom.
|
Correspondence to: Nilendran S. Prathalingam, Institute of Zoology, London,
NW1 4RY, United Kingdom (e-mail:
nprathalingam{at}rvc.ac.uk). |
The development of new technologies and software that are routinely used in
laboratories has now allowed for a more diverse novel range of methods to
determine sperm concentrations more rapidly. The aim of this study was to
compare 3 such novel methods developed in our laboratory, including a new flow
cytometry approach, image analysis, and a fluorescent plate reader, with more
conventional methods (hemocytometry, spectrophotometry, and Microcell
analysis). Fifteen ejaculates were collected from 13 bulls at an artificial
insemination center. The semen samples were analyzed for sperm concentration
using a spectrophotometer, hemocytometry, and a novel flow cytometry technique
based on counting a fixed volume of fluid. The raw ejaculate was also diluted
fivefold in a long-term diluent and sent overnight to another laboratory,
where sperm numbers were assessed using Microcells, an image analysis system,
and a fluorescent plate reader. Each ejaculate was assessed 5 times using each
of the methods described in order to determine the coefficient of variation
for each method. Comparisons between methods were determined using correlation
and limits of agreement. The flow cytometry results showed the lowest
coefficient of variation (2.3%), with the plate reader showing the highest
coefficient of variation (20.0%). There was no significant difference between
any of the methods used, and none of them consistently over- or underestimated
numbers when compared against each other. It is concluded that flow cytometry
showed the highest repeatability of results. However, the method employed by
each laboratory should be determined based on a range of factors, including
cost, convenience, sample size, and number of ejaculates to be assessed.
Key words: Cytometry, hemocytometry, microcells, spectrophotometry, plate reader
Copyright © 2006 by The American Society of Andrology.