In the case of highly elongated cells, transport to the cell extremities often poses a severe problem. For example, the filamentous fungus Neurospora crassa only grows at the apex of highly elongated cells called hyphae. All material destined for secretion at the hyphal apex needs to be transported to these growing tips.
N. crassa
is a fast growing organism. Its hyphae grow at a rate of about 7 cm per day,
requiring massive transport of scretory vesicles to the tip. A typical structure
in the tip of a growing hyphae is the Spitzenkörper which, in phase contrast
microscopy, appears as a dark body located within the hyphal apex. It consists
of an accumulation of small vesicles when viewed by electron microscopy.
How to
clean diffusion cells made of acrylic polymer without using any organic solvents
(alcohol)?
deconex 11 UNIVERSAL is compatible with acrylic polymer and the diffusion
cells can well be cleaned with deconex 11 UNIVERSAL. It also removes radioactive
contamination which can be a further important property when cleaning diffusion
cells.
What is the meaning of a validation?
Validation is the documented procedure required for obtaining, recording,
and interpreting the results needed to show that a process will consistently
yield a product complying with a pre-determined specification. The purpose
of validating a cleaning process is to test whether the quality of cleaning
agrees with the value stipulated according to the legal requirements.
What is biodegradability?
Bio-degradability is defined as complete biochemical decomposition of organic
molecules by microorganisms.
Biodegradability
reduces a substance being emitted into the environment or a substance being
retained by it. The more complete the biodegradation of a product within a
given time, the less important other ecological protection aspects become.
Generally materials are considered biodegradable if they degrade in the particular
test system after 28 days by more than 70 %.
How to distinguish between LD50 and LC50?*
LD50 (lethal dose) is the description for the quantity, mostly related to
weight, of a substance with which 50 % of the experimental animals (rat, oral)
die. It is a measure of toxicity with the following grading: