ref: 19-DENZ-500 385 Euro
gradient medium for cell separation.
Separations based on density differences: fractionation of
nucleic acids, proteins, polysaccarides and
nucleoproteins.Subcellular organelles can be successfully
isolated on gradients of Gentodenz under either isotonic or
mildly hypertonic conditions.Separation of intact living
cells.Useful in the isolation and purification of viruses
Gradients of Gentodenz can be
generated as follows:
1. Formed in situ by
centrifugation (self-forming gradients).
2. Layering solutions of the
desired concentration into an appropriate centrifuge tube
and allowing the solutions to diffuse. Using Gentodenz
isotonic solution gradients can be simply prepared in a
3. Freezing and thawing.
4. Gradients mixers
In literature the product, the applications, the procedures
are described.Over more than 30 years the density gradient
compound has been sold by several commercial companies under
different trade names.
Structure: non-ionic tri-iodinated derivative of benzic acid
with 3 aliphatic hydrophilic side chains.
Chemical name: 5- (N-2, 3-dihydroxypropylactamido)-2, 4,
6-tri-iodo-N,N’ –bis (2, 3 dihydroxypropyl) isophthalamide.
Purity: analytical grade min 99.20 %
Molecular weight 821.14
Density 2.1 g/ml
Gentodenz is non-ionc, non-toxic and is very water soluble.
Solutions up to 80 % (w/v) can be prepared. Aqueous
solutions have a very high water activity. Most particles
will are fully hydrated in solutions of Gentodenz and will
band at a low density. Solutions of Gentodenz are stable to
heat and may be autoclaved, stability to autoclaving
(enhanced by the addition of small amounts of Tris and EDTA.
Solutions of Gentodenz are very resistant to bacterial
degradation and Gentodenz is not metabolized by mammalian
The concentration and density of solutions of Gentodenz can
easily be determined by measuring the refractive index.
The relationship between concentration, refractive index (ŋ)
and density is linear and can be formulate:
Concentration, % (w/v) = 607.75 ŋ
Density (g/ml) =
3.242 ŋ – 3.323
(Before using this equation the refractive index must be
corrected for the presence of buffer or salt in the gradient
Gentodenz is a non-particulate medium;therefore the
distribution of cells in a gradient can be determined using
a haemocytometer, electronic particle counter or by
light-scattering measurements using a spectrophotometer.
Gentodenz is also soluble in formamide and dimethyl
non-aqueous denaturing gradients of Gentodenz.
Gentodenz in solid form is stable for a period of 5 years
when stored at room temperature and protected from light.
Gentodenz in solution is stable for 5 years provided that it
is kept sterile and protected from light. Prolonged exposure
to direct sunkight leads to release of iodine from the
molecule. This effect is negligible when working with these
solutions on a day to day basis.
Gradients solution for the
preparation of essentially iso-osmotic Gentodenz gradients
can be prepared using an iso-osmotic solution of Gentodenz
27.6% (w/v) Gentodenz
(density=1.15 g/ml) made up in buffered medium.
This solution may be diluted to
desired concentration by using a buffered diluent containing
either sucrose or NaCl as osmotic balancer.
The composition of these
diluents is as follows: 0.75 g NaCl or 7.45 g sucrose
Dissolved in 100 ml 5
mmol/Tris-HCl (pH 7.5) containing 3 mmol/l KCl and 0.3
mmol/l CaNa2 EDTA.
The relationship between
density and refractive index (ŋ) can be formulated:
Density = 3.287 ŋ –
3.383 Density = 3.410 ŋ – 3.555
Compatibility with some widely used assays:
Gentodenz does not interfere
with the orcinol and diphenylamine reactions for estimation
of nucleic acids, nor with the very sensitive dyebinding
assays for protein and DNA.
Polysaccharides and sugars can
be determined in the presence of Gentodenz using the
Fluorimetric assays of nucleic
acid and proteins can also be carried out in the presence of
Gentodenz does not interfere
with most assays for the marker enzymes of subcellular
components, also most commercial scintillants are compatible
Gentodenz from samples:
Gentodenz can be removed from
samples by dialysis, ultrafiltration and gel filtration.
Cells, subcellular organelles and other particulate matter
can be separated from Gentodenz by centrigugation without
the risk of contaminating the pellet with Gentodenz.
Gentodenz is readily soluble in
both acidic and ethanolic media. Thus in a number of cases
samples can be isolated free of Gentodenz by precipitating
the sample with trichloroacetic or ethanol.
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references : 50 gram ref19-DENZ-50
500 gram ref19-DENZ-500