Temperature Controlled Warm Stages Chosen for Sperm Motility in Human Fertility Testing

A Scottish NHS laboratory has chosen a Linkam THL60-16 warm stage as a reliable solution for the assessment of sperm motility. About 25% of couples are affected by fertility problems, with around 35% of men sub-fertile and 2% infertile. One of the services provided by the NHS is fertility testing and for men that means assessment of a semen sample. The concentration, motility and the morphology of spermatozoa are all assessed to determine fertility.

Sperm motility is temperature dependent. This warm stage can heat/cool from ambient to 60°C. To establish in-vivo fertility, observations need to be carried out at exactly 37°C to mimic conditions within the human body. The use of a precise, accurate heated warm stage is an essential part of the assessment. This is to ensure the assessment is conducted at a stable and specific temperature. Within the design of this Linkam warm stage a platinum resistor temperature sensor is used for higher accuracy and stability. A sophisticated CAD designed bi-filar heating element covers the entire working surface which provides a uniform temperature distribution in the sample slide. The Linkam stage gives the assessor the confidence that all samples are observed at a stable, set temperature.

A wet preparation is created for assessment. A sample is placed onto a clean glass slide and covered with a 22x22mm coverslip to provide a chamber approximately 20µm deep. The weight of the cover slip spreads the sample. Scientists initially look for aggregation or agglutination, and the presence of non-spermatozoa cells. The preparation is then observed at x400 magnification with a phase contrast microscope to observe motility. Each warm plate -designed by Linkam- is incredibly thin, as little as 0.5mm. This ensures that high resolution objective and condenser lenses can be used. Approximately 200 spermatozoa are counted and categorised 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.

Linkam warm stages are found in cell biology labs, hospitals and IVF clinics all over the world. The Linkam warm stages provide a simple, accurate, low cost temperature controlled platform that can heat/cool samples from ambient to 60°C.