Cellulose assays

Fibers and Fiber Sources. Fibers are present ia varyiag amounts ia food iagredients and are also added separately (see Dietary fiber). Some fibers, including beet pulp, apple pomace, citms pulp, wheat bran, com bran, and celluloses are added to improve droppiags (feces) form by providing a matrix that absorbs water. Some calorie-controUed foods iaclude fibers, such as peanut hulls, to provide gastroiatestinal bulk and reduce food iatake. Peanut hulls normally have a high level of aflatoxias. They must be assayed for aflatoxia and levels restricted to prevent food rejection and undesirable effects of mycotoxias. 

Pyrovatex CP coreacts on cellulose with an amino resin in the presence of a latent acid catalyst, to produce finishes durable to laundering (125,126). A higher assay version, Pyrovatex (CP New, has also been introduced. 

This Crude product (15.8 g) In water (360 ml) was added to a prehydrogenated suspension of 10% palladium on charcoal (4 g) in water (400 ml), and hydrogenation was continued for 30 minutes. The catalyst was removed and the filtrate was adjusted to pH 7.5 with sodium bicarbonate, then evaporated at low temperature and pressure. The residue was purified by chromatography on a column of cellulose powder, eluting first with butanol/ ethanol/water mixture and then with acetone/isopropanol/water. The main fraction was evaporated at low temperature and pressure to give a 32% yield of the sodium salt of a-carboxybenzylpenicillin as a white powder. The product was estimated by manometric assay with penicillinase to be 58% pure. 

The purpose of this study is only intended to illustrate and evaluate the decision tree approach for CSP prediction using as attributes the 166 molecular keys publicly available in ISIS. This assay was carried out a CHIRBASE file of 3000 molecular structures corresponding to a list of samples resolved with an a value superior to 1.8. For each solute, we have picked in CHIRBASE the traded CSP providing the highest enantioselectivity. This procedure leads to a total selection of 18 CSPs commercially available under the following names Chiralpak AD [28], Chiral-AGP [40], Chiralpak AS [28], Resolvosil BSA-7 [41], Chiral-CBH [40], CTA-I (microcrystalline cellulose triacetate) [42], Chirobiotic T [43], Crownpak CR(-i-) [28], Cyclobond I [43], DNB-Leucine covalent [29], DNB-Phenylglycine covalent [29], Chiralcel OB [28], Chiralcel OD [28], Chiralcel OJ [28], Chiralpak OT(-i-) [28], Ultron-ES-OVM [44], Whelk-0 1 [29], (/ ,/ )-(3-Gem 1 [29]. 

It may be necessary to purify the polymer on DEAE-cellulose before performing the polymer assay. 

The isoenzymes can be separated by electrophoresis on cellulose acetate, and Roberts, et al ( ) have described a method whereby the separated isoenzymes are eluted and then assayed kinetically. 

Figure 2. CM-cellulose chromatography of pectolytic enzymes. The activity peaks of the flow-through of a DEAE-cellulose chromatography was applied to a CM-cellulose column. The column was eluted with a NaCl (0-0.5M) continuous gradient at a flow rate of 34 ml/h. 10 ml fractions were collected and assayed for pectolytic activities Symbols (0) pectate lyase ( ) polygalacturonase (reducing sugar-releasing activity) (x) protein. Other details in Methods.

Chase and Long (1997) propose that this conundrum can be eliminated by the use of Zero Reference Materials (ZRMs) in analytical methods development to fully evaluate the method. A ZRM is a product matrix that lacks those nutrient components that are to be assayed, i.e. a blank matrix. The use of a ZRM in method development can and will give a true indication as to how the method will perform as the spiked nutrient levels approach zero. For example, two products. Corn Starch (NIST RM 8432) and Microcrystalline Cellulose (NIST RM 8416), contain very low elemental concentrations and could conceivably serve as real sample blanks or ZRMs in some analytical procedures. 

Brown et al.68 have developed a cellulose plate with a fluorescent indicator. Compounds are developed in 3.0% (w/v) NHfc.Cl and detected by fluorescence quenching. These authors also use 0.5% mercaptoethanol in their mobile phase, but this is only to prevent oxidation of the labile reduced pteridines, which are not adequately protected by substitution at the N5 position. Since neutral or alkaline solutions of leucovorin are relatively stable in air, this precaution may not be required for routine assay. 

Electrophoresis has also been employed to separate neomycin from analytically-interfering substances such as proteins. Hence Brammer and Hemsonl82 have determined the neomycin content of blood serum. Neomycin was separated from the serum proteins by electrophoresis on cellulose acetate and assayed colorimetrically following elution from the support. 

Municipal Sewage Treatment Plant. The reactors were batch-fed daily an RDF (refuse derived fuel) processed MSW feedstock obtained from Future Fuels Inc. in Thief River Falls, MN. The processed MSW feed contained 52% of dry weight (DW) cellulose, 20% lignin-plastics, 2% ash, and 26% acid-detergent solubles (% DW as determined by the acid-detergent-fiber assay (63)). The MSW feedstock was added to a nutrient solution at 5% w/v for daily feeding as previously described (55). 

In various runs, specific activity went from an average of 2.75 lU/mg protein (based on the Bio-Rad protein assay with bovine serum albumin standard) for Ae centrifuged crude preparation after alcohol precipitation, to 8 lU/mg after DEAE-cellulose chromatography, to 100 lU/mg after DEAE-Fractogel chromatography, to 1000 RJ/mg after Sephadex G-50 chromatography, and to 3200 lU/mg after CM-Trisacryl chromatography. 

Specificity. Under Ae conAtions of the assay, Xylanase II had little or no activity on cellulose, carboxymeAylcellulose, Avicel, and starch. 

Column Chromatography of Crude Toxin. The WSAP obtained from culture 350F was retained in the crude state for assay. The 266.2 mg of WSAP obtained from 350G was treated on successive columns of silicic acid, DEAE cellulose, and Sephadex G-15 and yielded a single semipurified toxic product (GT-4) of 23.1 mg or 9% of the starting crude extract (Table I). 

Salicylic acid and Its metabolite were separated by two methods. The first was thin layer chromatography on cellulose with BAW solvent as for the In vivo metabolism studies. A quicker separation was achieved with a polyamide column. The entire 400 pL from an individual assay was placed on top of a 0.8 x 2.0 cm column packed with Polyamide-6 (Accurate Chemical and Scientific Corp.). The salicylic acid metabolite was eluted with 6 mL water but salicylic acid was retained. 3a70B scintillation fluid (Research Product International Corp.) was used to determine the radioactive content of the entire 6 mL of eluant. Separation of salicylic acid and its metabolite by polyamide column chromatography was verified by thin layer chromatography. 

In searching for means to enhance this in vitro activity, a range of fungal isolates were screened for cellulolytic activity on straw. The tests used to assay activity included clearing of cellulose agar (zone size measured), loss of weight from straw, colony radial extension rate on a water-soluble extract... 

Another variant of the hybridization assay is the Northern blot. Here it is RNA, not DNA, that is separated on a slab gel and transferred to a membrane. In the original version of the method, a special chemically treated cellulose membrane was used to hold the RNA, since nitrocellulose does not normally bind RNA. However, conditions have now been found where nitrocellulose will indeed retain RNA molecules. Nylon membranes can also be used. Radiolabeled DNA probes and autoradiography are then employed as above in the Southern blot method. The method is often useful in studying how levels of RNA species in a cell vary with stages of development and differentiation. 

Hoffmann GF, Brendel SU, et al. (1992) Mevalonate kinase assay using DEAE-cellulose column chromatography for first-trimester prenatal diagnosis and complementation analysis in mevalonic aciduria. J Inherit Metab Dis 15 738-746... 

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