Polyvinylpyrrolidone coated silica

PercoU is a polyvinylpyrrolidone-coated silica sol with very low osmolarity. For cell separations therefore the osmolarity is adjusted to isotonic conditions by mixing 9 vol. Percoll stock suspension with 1vol. of 2.5 M sucrose, 1.5 M sodium chloride, or tenfold concentrated cell culture medium (e.g., 10 x RPMl). 

PAM, HYP AM and AM/AA copolymers can be analyzed by TSK Gel PWXL (44), TSK Gel PW (25, 44), Shodex OHpak (25, 45), CPG (31, 32, 33, 34, 38, 41, 46), Sephacryl SIOOO (39), polyvinylpyrrolidone-coated silica columns (36) with an appropriate mobile phase. For cationic acrylamide copolymers, the Gel TSK PW columns (44) have a better separation capability than the Gel PWXL columns. This is probably due to the higher number of residual anionic sites found in PWXL columns (44). When a cationic polyacrylamide is analyzed. 

Typical stationary phases include the following polyvinylpyrrolidone (PVP) coated silica sorbents, monodisperse non-porous silica columns with surface bound amides or ethers and composite agarose and polyacrylamide gels. The eluent normally consists of salts at concentrations greater than 1.0 M. Typical salts include sodium phosphate, sodium sulfate and ammonium sulfate, and organic acid salts like monosodium glutamate. Protein retention is stronger with salts that increase surface tension like phosphates, sulfates, citrates, which are solvated in water than with salts such as perchlorates and thiocyanates and the like. 

Polyacrylamide Polyethylene oxide Polyvinyl alcohol Hydroxy ethyl cellulose Polyvinylpyrrolidone Water (PW)-coated silica Mean pore diameter 100, 500, 1000 and 4000 A Column size 30 cm length 48 mm ID Water RI deteetor Universal ealibration 36... 

PEO, pDMA, and polyvinylpyrrolidone (PVP) have self-coating abilities, which allows DNA sequencing in bare fused-silica capillaries. A mixture of two molecular mass populations of PEO is possible to separate DNA sequencing fragments over 1000 bases, too, but the separation time exceeds 7 hr. pDMA and PVP are low-viscosity sieving matrices (<100 cP). They have moderate separation efficiencies and can provide maximum read lengths of about 500-600 bases. 

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