SERVA DNA Stain G is a safer alternative to traditional ethidium bromide stain for detecting nucleic acid in agarose gels. It is at least as sensitive as ethidium bromide and can b...
Ion Exchange Media
DOWEX® Ion Exchange Resins
DOWEX® resins are made of spherical particles. The benefit for the user is a highly efficient exchange process, due to optimal flow-through kinetics because of the round (spherical) particles.
We offer a broad range of DOWEX® ion exchangers (anion and cation) featuring small particle sizes and narrow particle size distributions (50 - 100 mesh, 100 - 200 mesh, 200 - 400 mesh). In addition, analytical grade qualities of DOWEX® resins are available. These products are processed from original DOWEX® (»practical grades«) resins, following a proprietory procedure developed by us.
DOWEX® 1 - anion exchangers of type I, strongly basic:
A series of gel ion exchangers based on styrene-DVB-copolymerisates of type I. Refers to U.S. Food Additive Regulations, Ref. 1.21.1148
Supplied form of all DOWEX® anionic resins:
pract. grade = Cl- form
analytical grade = Cl- form
Maximum working temperature for all DOWEX® anion resins listed:
100 °C for Cl- form
60 °C for OH- form
For other counter ions please inquire for special bulk production.
DOWEX® 50 W - cation exchangers, strongly acidic:
Spherical beads, sulfonated polystyrene/ DVB matrix.
Supplied form of all DOWEX® 50 W resins:
pract. = H+ form
analytical grade = Na+ form
Maximum working temperature for all DOWEX® cation resins listed:
120 °C for Na+ form
120 °C for H+ form
For other counter ions please inquire for special bulk production.
DOWEX® is a trademark of Dow Chemical Comp., Michigan, USA.
DOWEX® Ion Exchange Resins
SERDOLIT ® Ion Exchange Resins
Analytical Grade Qualities for the Laboratory
Ion exchangers are produced for technical purposes (practical grade). In this stage they contain a considerable amount of impurities which must be carefully removed for making them suitable for (bio)chemical purposes. In addition, smaller and better defined particle sizes are desirable. The SERDOLIT® resins have been purified with particular care to meet these requirements.
SERDOLIT ® Ion Exchange Resins
SERDOLIT ® Polymeric Adsorbent Resins
Whereas with ion exchangers (mainly) charged molecules can be adsorbed and/or separated, neutral adsorbent resins (Polymeric ADsorbents: SERDOLIT® PAD Resins) can be used for the extraction and in some cases even for separation of neutral, basic and acidic substances. This adsorption process often is performed with compounds which are dissolved in water or in a solution which does not contain too much of an organic solvent that might prohibit the interaction (van der Waals forces, hydrophobic, hydrogen bridges) between adsorbent and adsorbate.
We offer two types of SERDOLIT® PAD Resins: polar and apolar. The unpolar types (SERDOLIT® PAD I, II, III) are copolymerisates of polystyrene and DVB, whereas the polar is a polymerized methacrylic acid ester (SERDOLIT® PAD IV).
Apolar resins (PAD I - III) bind organics from water, polar SERDOLIT® PAD IV even from organic solvents. Unwanted substances (impurities, salts) are eluted with water, the enriched compound(s) with water mixable organic solvents. Their eluotropic forces are known from chromatographic experience. Acidic molecules are best eluted with basic eluents, basic molecules under acidic conditions.
SERDOLIT ® Polymeric Adsorbent Resins
SERDOLIT ® Chelating Resins
SERVACEL® Cellulose Ion Exchangers
Cellulose ion exchangers have a very loose hydrophilic network (no pores) with well separated charged groups. Ionic macro(bio)molecules are adsorbed to only a few sites which can be desorbed selectively under extremely mild conditions with high recoveries. pH stability is excellent between 3 and 12. Storage of DEAE-cellulose in 2 M NaOH for 4 months at 50 °C does not change capacity for proteins. In order to provide greater stability and pressure resistance, the cellulose matrix can be produced in »regenerated« microcrystalline form. Here the particles are granular and the amorphous (fibrous) part of the cellulose fibers is removed. For additional stabilization the fibers are crosslinked.
SERVACEL® CM 52 and DEAE 52 are microcrystalline and thus allow a more dense packing: a superior resolution can be obtained compared with fibrous material. In addition, they are supplied in pre-swollen form to facilitate handling: they are ready-to-use after equilibration with the selected buffer system. They do not require the time consuming "pre-cycling" procedure (washing with acid resp. alkali) which is necessary with cellulose ion exchangers supplied as dry powder.
CM-Cellulose - Cation exchangers (acidic type):
Cellulose is derivatized with CarboxyMethylchloride. The resulting weakly acidic high capacity exchanger can be used for neutral and basic proteins, peptides, lipids.
DEAE-Cellulose - Anion exchangers (basic types):
DiEthylAminoEthyl-groups are covalently bound to the cellulose hydroxylic groups. This anion exchanger can be applied for the chromatography of proteins with neutral or
acidic isoelectric points (IP), which can easily be determined by isoelectric focusing electrophoresis (IEF). Serum components, enzymes, peptides, polysaccharides, RNA-types, viruses, lipids and ribosomes have been separated. DEAE cellulose is suitable for purification of nucleic acids.
SERVACEL® Cellulose Ion Exchangers
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SERVALYT™ Carrier Ampholytes SERVALYT™ Carrier Ampholytes are low molecular weight molecules of zwitterionic character. They are a mixture of synthetically derived species of avera...
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IPG Strips for 1D / 2D GE SERVA IPG BlueStrips are dried gel strips with immobilized pH gradient used in high resolution 2D gel electrophoresis of proteins. The strips have to be r...
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Detection Reagents Before membrane bound antigens can be detected, unspecific binding sites for antibodies on the transfer membrane have to be blocked. For many applications skim ...
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Agarose Media The electrophoretic behavior in gels of DNA and RNA is effected by their size and shape. Both RNA and DNA can exist as single and double stranded molecules and the s...
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Staining Kits Depending on the required sensitivity protein gels are Coomassie®-, silver or fluorescence stained after electrophoresis.Besides SERVA DensiStain Blue G for rapi...
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