Laser microdissection
Cantact-free - Contamination-free
How microdissection works:
PALM MicroBeam from Carl Zeiss enables contact-free collection of samples from biological specimen including live cells in culture. By a precisely controlled laser pulse the selected specimen is ejected vertically out of the object plane and into a collection device – against the force of gravity. This non-contact Laser Capture Microdissection (noncontact LCM) process is unique to PALM MicroBeam system and is an invaluable innovation for scientific research and medicine. Its contact-free mode of action makes LCM beneficial particularly in the field of pathology, but due to its purity it is used also in stem cell research or forensic medicine.
Example: Tumor Biology
Laser microdissection often is a precondition to get reliable new insights in the regulation of invasion and metastasis, angiogenesis and cell cycle kinetics.
Non-contact LCM of a prostate carcinoma gland.Courtesy of Dr. Thorsten Schlomm, UKE Hamburg
The genetic material of a cancer cell has undergone a number of changes that fi nally can no longer be corrected by intrinsic repair mechanisms. The cell breaks out of the sophisticated balance of growth and renewal and begins to proliferate uncontrolled.
Thus, to develop new approaches in cancer diagnostics and treatment, we need to understand the complex biochemical processes inside cells and also the infl uences of interactions between each other. Focus of research can be the mechanisms of cell differentiation and the regulation of cell-type specifi c proteins and their functions as well as the investigation of changes in the genetic material that cause or promote tumor development.
Analyzing bulk material which by nature can be very heterogeneous bears a high risk of bias in the molecular results. In contrast, accurately selected sample material allows reliable studies without distortion by irrelevant or disturbing tissue fractions.
The methodological combination of laser microdissection and transcriptome analysis allows extensive studies of gene expression on precisely defi ned cellular material – completely contamination free.
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Non-contact LCM of a kidney biopsy sample
a – outlining and cutting
b – section after non-contact LCM
c – sample area inside the collection device |
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Example: Cancer – from Death Sentence to Chronic Remission
Worldwide breast cancer is by far the most common type of cancer in women, both in incidence and death.
Her2-positive breast cancers tend to be more aggressive than other types of breast cancer. Routine testing is recommended for most women with breast cancer because the results may effect treatment recommendations and decisions. In about a third of patients having metastasizing breast cancer the Her2/neu protein is overexpressed in breast tissue. This is the result of a gene amplification and/or overexpression of the HER2 gene coding for a specific receptor. The detected over-expression rate varies. Conventional chemo- and hormone therapies are less effective in Her2/neu overexpressing patients. But in total contrast to former times Her2 positive patients (grade 3+) now have a better prognosis if they are treated with a monoclonal antibody that blocks the Her2 receptor on the surface of breast cancer cells. A prerequisite for the treatment with this antibody is the diagnostic confirmation of HER2 overexpression in the tumor cells.
Today’s routine is staining of biopsy material with a monoclonal antibody against Her2. The results depend on various factors like fixation of the tissue, antibody and technique used, and interpretation of the staining result. In those biopsies tumor cells with amplified HER2 DNA may be dispersed in a background of normal cells with nonamplified DNA. A new approach is therefore the isolation of clearly outlined tumor material from stained sections via non-contact LCM followed by molecular analysis of these precisely selected tumor cells.
