Glutaraldehyde concentration

Swedish hospital workers exposed to low glutaraldehyde concentrations (below 0.2 ppm) had an increased frequency of reported nose and throat symptoms, skin symptoms such as eczema and rash, and general symptoms such as headache and nausea, compared with unexposed controls. ... 

FIGURE 8.9 Effect of glutaraldehyde concentration on release profile of D-arabinose from gelatin microparticles (D-arabinose loading 16%) in 1/15 M phosphate buffer (pH 7.4) at... 

The Effect of Glutaraldehyde Concentration on the Absorption of D-Arabinose and PS1 from the External or Internal Surface of Gelatin... 

FIGURE 8.12 Response-surface diagram for the mean particle diameter of albumin microparticles prepared by variation of glutaraldehyde concentration and duration of cross-linking. (From Oner, L. and Groves, M.J. (1993b). J. Pharm. Pharmacol., 45, 866-870. With permission.)... 

Instead of whole-mount cells, it is also possible to prepare thin sections. Cells are grown on plastic coverslips, fixed (glutaraldehyde concentration lowered to 2%), hybridized and the label detected as described above. The cells are then postfixed with 2% OSO4 in PBS for 30 min and dehydrated in graded alcohol. They are then passed through 100% alcohol/Epon (1 1) for 1 h at room temperature and 1 h in 100% Epon. Beem capsules filled with Epon are quickly inverted onto the surface of the coverslip and oven-baked at 60°C for 48 h. The Beem capsule and coverslip are removed followed by routine ultrathin sectioning and processing. 

The composition of the fixative may vary depending on the sensitivity of the antigen. For some antigens, it may be necessary to reduce the glutaraldehyde concentration or omit it entirely, and fix in 4% formaldehyde in PBS for 1—4 h. 

System variables that affect the efficacy of glutaraldehyde as a biocide include temperature, flow velocity, and glutaraldehyde concentration, but the most important factor is pH. 

The effect of concentration on a mixed culture at different pH was demonstrated by Grab et a/[1990] and is shown on Fig. 14.23. a combination of pH 8.1 and a glutaraldehyde concentration of 200 mg/l gave a remarkable rate of kill, i.e. reducing viable cell numbers from around 5 x 10 to near zero in about 1 hour. 

Immobilized Alternarla tenulsslma cells were prepared by a procedure ensuring the maximum proportion of the bound cell fraction. Preliminary experiments revealed that the efficiency of immobilization is markedly affected by the manner of carrier activation (reaction time and glutaraldehyde concentration). The age of mycelium has no significant effect. 

At 0.2 0 glutaraldehyde concentration there is a relatively law probability of cross-linking and hence a relatively low number of active cross-link sites. Therefore, a plateau of UTS is reached rather than a peak since the active sites in the surface region are used up and cross-linking ceases. Cross-linking has therefore been stopped before the surface imperfections have become an lified as stress concentrations. This allows fibers to be cross-linked for the "optimum time which heretofore was impossible due to the manual nature of the fiber production procedure. 

For a cross-linking time of three minutes the optimum glutaraldehyde concentration is 0.5 for both collagen and five percent... 

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