What are the key indicators of sperm viability?
Sperm viability, and therefore a man’s fertility, can be determined by analysis of the concentration, motility and the morphology of his spermatozoa. This is a part of Andrology, from the Greek Andros “man”, the medical field that deals with male health including problems associated with the reproductive system.
Concentration is an estimation of spermatozoa per ejaculate. If the concentration is low – known as Oligozoospermia - this indicates he has a reduced chance of fertilisation.
Morphology is another way to describe the appearance of the spermatozoa.
Spermatozoa consist of a head, a midsection and a tail and abnormalities can cause fertility problems.
Motility is characterised by the direction and speed of the spermatozoa. Low motile sperm may lack the ability to move to the location of the egg and so this directly impacts fertility.
How are these indicators assessed?
The currently accepted criteria being used in UK laboratories are set out in the WHO laboratory manual for the Examination and processing of human semen, 5th edition.
The terms do describe abnormal parameters are usually used when the parameter (motility, concentration or morphology) fall below the reference values. These are currently (32%, 15 million per ml and 4% normal forms respectively).
Samples are observed visually using light microscopy. A scientist initially looks for aggregation or agglutination of the spermatozoa, and the presence of non-spermatozoa cells. Pyospermia and Hematospermia are conditions where abnormal cells (white/red blood cells) are found within the seminal fluid.
The sample is also observed at x400 magnification with a phase contrast microscope to observe motility. Approximately 200 spermatozoa are counted and categorized to determine the percentage of each category. Spermatozoa can be classified as progressively motile, non-progressively motile or non-motile. The percentage of progressively motile sperm is important to fertility assessment. Progressively motile sperm exhibit movement across the assessment medium; criteria such as straight line velocity and average path velocity can all be observed.
Why is sperm motility temperature dependent?
Sperm motility is controlled by energy, and biochemical pathways produce this power within the mitochondria, organelles located in the mid-section of the spermatozoa.
All biochemical -and enzyme reactions in particular- proceed faster as the temperature increases. Thus, motility is temperature dependent. The fertility of sperm needs to be assessed at 37°C as this best reflects the behaviour of sperm in vitro. Irregular control of temperature makes it extremely difficult to compare samples.
It is essential that samples that are to be compared are analysed at the same temperature. Routinely in fertility testing, two samples are analysed so the results can be averaged to get a clear understanding of the patient’s health. In another application, results post and pre-op may also be compared to quantify the effectiveness of surgery. Hotter or colder temperatures may lead to misleading diagnoses of the patient’s fertility.
Can you give a brief introduction to Linkam’s warm stages? It has recently been reported that they have been chosen by a number of laboratories in the UK for sperm assessment?
The use of a precise, accurate, warm stage is an essential part of fertility assessment. This is to ensure the analysis is conducted at body temperature. Linkam warm stage design incorporates a platinum resistor temperature sensor for accuracy and reliability. Each has a sophisticated CAD designed bi-filar heating element that covers the entire working surface. This provides uniform temperature distribution within the sample. To ensure that high resolution objectives can be used each warm plate is incredibly thin, as little as 0.5mm.
The warm stage gives the assessor the confidence that all samples are observed at a stable, set temperature. The Linkam warm stages provide a simple, accurate, low cost temperature controlled platform that can heat/cool samples from ambient to 60°C.
Each warm stage is controlled by a DC95 controller.
The sleek design with tactile touch screen interface is easier to use than ever, and with a small physical volume that can be accommodated on the busiest of scientific benches.
Warm stages can be used for the assessment of both human and animal sperm and have been used worldwide to support veterinarians and zoologists with their work. Species preservation in Africa, evolutionary studies in Sweden and animal husbandry in the UK all benefit from the use of a warm stage.
How do Linkam’s warm stages compare to others on the market?
Linkam Temperature Stages are recognised around the world for their excellent temperature control. The warm stages are part of Linkam’s range of high accuracy instruments.
What plans do Linkam have for the future?
We are actively working with scientists within this area and are looking at increasing our range of instruments soon.
Would you like to make any additional comments?
We develop and manufacture a range of heating and freezing microscope stages for both OEM and end users to visualize and explore materials properties. Used in conjunction with light microscopes, Raman, IR and other forms of spectroscopy, Linkam stages are found in thousands of laboratories worldwide with the most successful heating/freezing stage, the THMS600, selling over 4000 units alone.
Where can readers learn more information?
Please find more information at: http://www.linkam.co.uk/warm-stages-features/
About Caroline Feltham
Caroline is the Technical Sales and Marketing Executive at Linkam Scientific Instruments, responsible for the creation of marketing material for the popular Linkam products. She is also part of the international sales team, supporting both direct clients and overseas distributors with quotes and technical information.
Caroline joined Linkam in 2011 after working in a highly successful independent UKAS accredited laboratory. With a background in the lab, Caroline is experienced in the handling and use of multiple concentrated chemicals such as liquid HF acid, cyanide and chlorine gas.
With a Bachelor of Science Degree in Forensics, Caroline has a strong understanding of many analytical techniques and disciplines.
Caroline is an avid dancer, writer and is actively involved in local drama productions. She lives in Surrey, UK.