JPK reports on the research
activities of Dr Jochen Guck and his
teams at Dresden & Cambridge Universities

JPK Instruments, a world-leading manufacturer of nanoanalytic instrumentation for research in life sciences and soft matter, reports on the multi-faceted research projects of Dr Jochen Guck who runs simultaneous research at the Universities of Dresden and Cambridge.

Picture: Dr Jochen Guck's PhD student in Cambridge, Kathrin Holtzmann, working with JPK's NanoWizard® AFM.

The biophysicist Dr. Jochen Guck has recently started his Humboldt Professorship of Cellular Machines at the Biotechnology Center of the TU Dresden (BIOTEC) while continuing to lead a team at the Cavendish Laboratory at Cambridge University (UK). His work at BIOTEC focuses on the development of new biophysical approaches for stem cell research, blood cell diagnostics and neuroregeneration. One of his main tools for characterization of biomaterials are the NanoWizard® systems from JPK Instruments. Unlike many other users, he does not apply them for basic scanning measurements but uses them to study cellular behaviour and to quantify their interactive forces.

Talking about his research, Professor Guck said "Most of our work uses AFM for mapping the mechanical properties of tissues. It is starting to be recognized that cells respond to the mechanical properties of the environment they are in contact with. They can differentiate into different lineages when in contact with stiff or compliant surfaces. Or they migrate towards stiffer areas or softer areas - a phenomenon called durotaxis. We are one of the few groups that have started to consider this mechanosensitivity of cells in the CNS; in the context of neural development and pathological disorders. One important prerequisite for these studies is to know quantitatively, how stiff or how soft CNS tissues actually are so that we can mimic this environment in vitro, and whether there are heterogeneities that cells could respond to. If everything is the same, there is no queue for migration for example. This is where we have pioneered the use of AFMs for the mapping of mechanical properties of CNS tissues with high spatial resolution."

Continuing about his experiences in working with JPK, he said "NanoWizard is perfect for measuring mechanical properties of biological cells and tissues, while keeping the cells and tissues in their physiological environment at the right temperature and their preferred medium (BioCell™). And, we can correlate mechanical mapping with optical microscopy such as bright-field or fluorescence microscopy. This helps us to know what we are actually measuring: which cell type, which state (quiescent or activated) or which area in a tissue."

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Linkam Scientific Instruments, have been chosen
by an NHS Fertility clinic as suppliers of a controlled warm
stage to perform routine semen analysis at body temperature

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 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.

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.

The design, reliability and versatility make the Linkam warm stage an essential tool for sperm motility testing.

For further information, about the broad range of applications in the field of temperature controlled microscopy, view website: www.lc-vision.com  Refer to next page

VHX-2000 - Super resolution digital
microscope with automated measurements

Pioneering the field of digital microscopy, KEYENCE has released its latest microscope system, the VHX-2000. The VHX Series Digital Microscope was designed to alleviate the shortcomings of traditional, optical light microscopes - shallow depth-of-field, short working distance, lack of portability and versatility, sample limitations, etc. By integrating advanced zoom optics with a CCD camera, 17" LCD monitor, light source, controller and analysis/reporting software, the VHX streamlines testing and improves the speed and efficiency of the inspection process.

With a magnification range from 0.1x - 5000x, the VHX Series enables a wide range of microscopic observation from macro-scale stereoscopic imaging to the detailed analysis of an SEM. Many lighting techniques are also supported including bright and dark field, transmitted, polarised, and differential interference observation.

Building on top of the VHX platform, the VHX-2000 incorporates several new features. A colour filter wheel has been added to allow users the option of choosing a specific wavelength (red, green or blue) of light for their samples. A Super Resolution mode combines the blue filter with KEYENCE's pixel shift technology, capturing images with 25% better resolution.

To improve the operation and ease-of-use, the VHX-2000 can be equipped with a motorised XY stage along with motorised Z-axis lens control. Users can adjust movement in all three axes by using an included control pad. When combined with our Double'R lens/magnification recognition function, the VHX-2000 can automatically provide the ideal movement speed for the XY stage and enables one-push automatic focus and calibration. The Image Stitching function can now be completed with just the push of a button, and at much higher speeds, to produce up to a 20,000 x 20,000 pixel image that expands the viewing area by up to
200 times.

Automated measurement functions simplify the most difficult of measurement tasks and help to remove variation between different users. The system also has the ability to save a portion of the image/measurements as a template to be used to measure future samples with a click of the mouse.

For further information on the VHX-2000 Digital Microscope specifications and applications, view website: www.keyence.co.uk/prvhx2