The ICGI runs several active and specialized laboratories, with skilled personnel contributing to the increasing demands of tissue and cell preparation for diagnostics and research.
Fixation and embedding tissue in paraffin blocks: Tissue samples for histological evaluation are fixed in formalin to prevent degradation. This stabilizes the structure of the tissue and cell composition. Following fixation, the tissue is dehydrated and embedded in paraffin.
Sectioning: Paraffin-embedded tissue is sliced using a rotation microtome. Thin sections are placed on glass slides, in preparation for staining, treatment and analysis.
Preparation of monolayers: At the ICGI we have developed a specific method for obtaining a pure nucleic suspension by enzymatically treating scrolls of tissue and rinsing away the unwanted cell components and surrounding tissue. The nuclei are spun onto a slide in one layer using a cytospin centrifuge.
HE staining: Hematoxylin and eosin staining is regularly performed to visualize the tissue structure and plan further analyses. Hematoxylin stains the cell nucleus while eosin stains the cytoplasmic proteins and surrounding structures.
Feulgen-Schiff staining: Sections and monolayers are stained using Feulgen for DNA- and chromatin analyses. The Feulgen stain intensity is proportional to the DNA content, which enables the quantification of DNA in ploidy and texture analyses.
Immunohistochemistry: A staining method based on antigen-antibody reactions. This allows us to quantitatively assess the presence of gene products in cells.
Microscope measurements: Stained tissue sections are analyzed microscopically. We have developed robot-controlled measuring stations, which automatically locate the area of interest and adjust focus and light intensity before images are grabbed, processed and analyzed.
Scanning: Tissue sections are scanned using NanoZoomer scanners. The NanoZoomers digitalize up to 200 sections per batch, and offer optimal-quality images. The digital images are further analyzed with various software and are used for verification of tumor area, web-based applications like
Cell culturing: For cytogenetic analyses live cells are cultured. They are incubated for 24 hours before being harvested.
Cell harvesting: Cultured cells are arrested in cell cycle and harvested. For cytogenetic analyses the cells in metaphase are selected as these allow for analyses of chromosomes. To prevent cell division, Colcemid is applied.
Dripping: Cultured cells are dripped onto the testing material one by one, rupturing the cells and exposing the chromosomes.
Leishman staining: The chromosomes are denatured with trypsin and stained with Leishman. This gives the chromosomes a characteristic and reproducible pattern of light and dark bands.
Comparative genomic hybridization (CGH): Comparing DNA samples for detection of unbalanced chromosomal abnormalities.
Fluorescent in-situ hybridization(FISH): FISH is used to determine the location of a specific DNA or RNA sequence by hybridizing it with a fluorescent probe. FISH is used as a complementary analysis to karyotyping, to detect small deletions and rearrangements in chromosomes. FISH is also used to determine the presence or absence of candidate genes associated with large scale genomic instability.
This text was last modified: 10.03.2017