CASA in the medical laboratory: CASA in diagnostic andrology and assisted conception.

CASA has been used in reproductive medicine and pathology laboratories for over 25 years, yet the 'fertility industry' generally remains sceptical and has avoided automation, despite clear weaknesses in manual semen analysis. Early implementers had difficulty in validating CASA-Mot instruments against recommended manual methods (haemocytometer) due to the interference of seminal debris and non-sperm cells, which also affects the accuracy of grading motility. Both the inability to provide accurate sperm counts and a lack of consensus as to the value of sperm kinematic parameters appear to have continued to have a negative effect on CASA-Mot's reputation. One positive interpretation from earlier work is that at least one or more measures of sperm velocity adds clinical value to the semen analysis, and these are clearly more objective than any manual motility analysis. Moreover, recent CASA-Mot systems offer simple solutions to earlier problems in eliminating artefacts and have been successfully validated for sperm concentration; as a result, they should be viewed with more confidence in relation to motility grading. Sperm morphology and DNA testing both require an evidence-based consensus and a well-validated (reliable, reproducible) assay to be developed before automation of either can be of real clinical benefit.

Standards in reporting cryopreserved donor sperm characteristics: should they be reported post-thaw or post-wash?

An increase in the reliance on imported donor samples has been the consequence of a continued shortage of UK donors. Disputes can arise between suppliers and purchasers if the sperm quality is not as expected, yet there appears to be no requirement for the standardization of methods for sperm processing or analysis. Following analysis of 102 donor intrauterine insemination cycles, this study demonstrates that the motile sperm concentration is significantly (P < 0.05) reduced after the necessary removal of cryoprotectant before insemination. Suppliers of donor spermatozoa should therefore provide information on standards used for sperm assessment and whether analysis is performed before or after washing in order that purchasers are better informed about the quality of the end product they are committed to buying.

Recovering the dynamics of root growth and development using novel image acquisition and analysis methods.

Roots are highly responsive to environmental signals encountered in the rhizosphere, such as nutrients, mechanical resistance and gravity. As a result, root growth and development is very plastic. If this complex and vital process is to be understood, methods and tools are required to capture the dynamics of root responses. Tools are needed which are high-throughput, supporting large-scale experimental work, and provide accurate, high-resolution, quantitative data. We describe and demonstrate the efficacy of the high-throughput and high-resolution root imaging systems recently developed within the Centre for Plant Integrative Biology (CPIB). This toolset includes (i) robotic imaging hardware to generate time-lapse datasets from standard cameras under infrared illumination and (ii) automated image analysis methods and software to extract quantitative information about root growth and development both from these images and via high-resolution light microscopy. These methods are demonstrated using data gathered during an experimental study of the gravitropic response of Arabidopsis thaliana.

High-throughput feature counting and measurement of roots.

SUMMARY: The original RootTrace tool has proved successful in measuring primary root lengths across time series image data. Biologists have shown interest in using the tool to address further problems, namely counting lateral roots to use as parameters in screening studies, and measuring highly curved roots. To address this, the software has been extended to count emerged lateral roots, and the tracking model extended so that strongly curved and agravitropic roots can be now be recovered. Here, we describe the novel image analysis algorithms and user interface implemented within the RootTrace framework to handle such situations and evaluate the results. AVAILABILITY: The software is open source and available from http://sourceforge.net/projects/roottrace.

Validation of a novel computer-assisted sperm analysis (CASA) system using multitarget-tracking algorithms.

OBJECTIVE: To determine the accuracy and precision of a novel computer-assisted sperm analysis (CASA) system by comparison with existing recommended manual methods. DESIGN: Prospective study using comparative measurements of sperm concentration and motility on latex beads and immotile and motile sperm. SETTING: Tertiary referral fertility center with strong academic links. PATIENT(S): Sperm donors and male partners of couples attending for fertility investigations. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Achievement of Accubead target value for high and low concentration suspensions. Repeatability as demonstrated by coefficients of variation and intraclass correlation coefficients. Correlation and limits of agreement between CASA and manual methods. RESULT(S): The CASA measurements of latex beads and sperm concentrations demonstrated a high level of accuracy and repeatability. Repeated Accubead measurements attained the required target value (mean difference from target of 2.61% and 3.71% for high- and low-concentration suspensions, respectively) and were highly reproducible. Limits of agreement analysis suggested that manual and CASA counts compared directly could be deemed to be interchangeable. Manual and CASA motility measurements were highly correlated for grades a, b, and d but could not be deemed to be interchangeable, and manual motility estimates were consistently higher for motile sperm. CONCLUSION(S): The novel CASA system was able to provide semen quality measurements for sperm concentration and motility measurements which were at least as reliable as current manual methods.