Increasing precision and reducing variation in sperm assessments using the Sperm Class Analyzer®
Rothman C, Sims CA, Shamonki J, Schiewe MC.
California Cryobank (CCB), QC/R&D Lab, Los Angeles, CA 90025, USA.
Background
CCB endeavors to optimize precision of sperm count and motility calculations by reducing potential procedural sources of variation. The adaptation of real-time video imaging software has made Computer Assisted Semen Analysis (CASA) more versatile and practical for the end users. In fact, this technology allows for remote capturing of video images (i.e., satellite labs) to be processed at one central location, thus eliminating inter-technician/facility variation.
Objective
This prospective validation study aims to compare sperm concentration and motility determinations by manual (Makler chamber) or automated (Sperm Class Analyzer {SCA}, Microptics) methods. Two different technicians (one per method) were used to eliminate technical bias.
Methods
50 specimens were acquired from men being evaluated as potential sperm donors. Consent was obtained from all participants. Semen analysis was performed on each sample in concurrence with an IRB-approved, FDA-supported validation trial of the SCA unit. The standard manual evaluation of each sample consisted of duplicate or triplicate counting of 20 grids per analysis on a Maker chamber. For the SCA analysis we loaded Leja SC 20 disposable slides with 5 μl of sample per chamber and placed it on a standard phase contrast microscope. Using the SCA Motility program, at least 5 separate fields were captured using a 10X objective under green-filtered low light. Centralized regions from the opening to the base of the chamber were documented. The highest and lowest sperm concentration outliers were eliminated.
Results
The SCA-CASA system assessed an average of 848 sperm/analysis, while Makler chambers evaluated 83 sperm/analysis. The mean concentration of specimens analyzed with the Makler was 10.9% lower than those analyzed with the SCA (64±3.6 vs 71.8±2.3, x106/ml). The manual method produced greater dispersion in motility estimates; total motility estimates were lower (48±5.4% vs 61±3.8%; 22% variation) and progressive motility estimates higher (32±4% vs 21±2%; 55% variation).
Discussion
The reproducibility of sperm count and motility calculation will always be subject to a degree of variation inherent to this biological product. Eliminating procedural variation and optimizing technician precision are important QC laboratory goals. A centralized SCA unit has the potential to provide superior evaluation and video documentation of specimens. Additional verification studies are needed to resolve why differences in motility exceed 20% differences in motility when compared to manual estimates.
Support
Microptic, Barcelona, Spain; ASPIRE IRB, LaMesa, CA.
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