Pathology Archives

Genetadi Biotech (Derio, Spain) has developed a chip that is capable of detecting 150 different genetic syndromes from a few milliliters of amniotic fluid. It uses comparative genomic hybridization micro-array technology to identify areas with differences in hybridization between patient and control DNA. This technology allows for a diagnostic resolution much higher than with conventional techniques and spots several syndromes not detected with regular karyotypes. For the patient the procedure has not changed – an amniocentesis is still needed to collect the amniotic fluid, which is only recommended in pregnant women at risk for carrying a fetus with a syndrome. Results are available much faster though, within 48 hours. The Amniochip was presented at the XXVI Spanish National Congress on Human Genetics. A short overview of the technology from, the press release:

The new device for enhanced prenatal diagnosis, developed by Genetadi “is based on Comparative Genomic Hybridisation” (aCGH) microarray technology. Using this technique, “the sample to study and a reference are marked with different fluorochromes. These DNA hybridise on a crystal which contains thousands of different segments of human DNA. The regions selected on the Amniochip belong to regions of the human genome involved in more than 150 already known syndromes. Subsequently, computer software is used to identify the areas of differential hybridisation between the patient and the DNA control, thus indicating the existence of an alteration in its dosage (microdeletion or microduplication)”.

Read More

Scientists at Howard Hughes Medical Institute’s Janelia Farm Research Campus have developed a new microscopy technique that uses light to virtually slice through living cell samples. Known as Bessel beam plane illumination microscopy, the technique currently produces slices less than 0.5 μm at a rate of over 200 per second. The high rate of slicing allows for movies to be made of the inner workings of living cells. See for yourself:

Although other researchers, including Janelia Farm Fellow Philipp Keller, have used plane illumination to great effect to study multicellular organisms hundreds of microns in size, the light sheets were still too thick to work effectively for imaging within single cells only tens of microns in size. The main problem is that the wide swath of light used in plane illumination exposed more of the cell than Betzig’s group wanted. This caused excessive blur and light toxicity. To circumvent this problem, his group used a Bessel beam, a special type of non-diffracting light beam studied by physicists in the late 1980s, and used today in applications including bar-code scanners in supermarkets. Sweeping the beam across the sample creates a thinner light sheet, his group found.

Read More