Millipore filter

The sampling of solution for activity measurement is carried out by filtration with 0.22 pm Millex filter (Millipore Co.) which is encapsuled and attached to a syringe for handy operation. The randomly selected filtrates are further passed through Amicon Centriflo membrane filter (CF-25) of 2 nm pore size. The activities measured for the filtrates from the two different pore sizes are observed to be identical within experimental error. Activities are measured by a liquid scintillation counter. For each sample solution, triplicate samplings and activity measurements are undertaken and the average of three values is used for calculation. Absorption spectra of experimental solutions are measured using a Beckman UV 5260 spectrophotometer for the analysis of oxidation states of dissolved Pu ions. 

The basal medium of Mandels (Mandels et al., 1976) was used with the following modifications it was buffered with 3 g/1 of sodium nitrate to pH 5.5 and supplemented with 1% w/v citrus pectin " Sigma" or other carbon sources. For enzyme production, 50 ml medium in 250 ml erlemneyer flasks were inoculatedwith spores (10 spores /ml ) exept for the non sporulating Pol 6 strain, where mycelium was used. The culture were incubated at 30° C on a rotary shaker (150 rev mn -1) for 5 days. The culture broth was filtered (Millipore 0.45 pm ) and the supernatant was analysed for pectinolytic activities, reducing sugars and proteins. 

The samples of crude and distillate for GPC analysis were prepared by dissolving the sample in dry additive-free THF to obtain a 25% solution and the solution was filtered through micro-pore filters (Millipore, 0.5 micrometer size). A solution containing both the calibration standard and the sample was used to determine the molecular size distribution of the sample. 

Refractive Index Detector (Knauer). The KMX-6 scattering intensity was measured with the 6-7 degree forward-scattering annulus. A series of Zorbax PSM columns (DuPont) was used PSM 60, PSM 1000, PSM 1000, PSM 60, PSM 1000. Tetrahydrofuran (THF) from Baker was filtered through a 0.22 micrometer Fluoropore filter (Millipore Corp.) before use in chromatography, and a flow rate of 0.7 ml/min was used. 

Samples were either prepared by direct addition of polymer to solvent (Method I) or by a careful method to reduce dust (Method II) In Method II, PBLG was added from a stock solution in distilled DMF via a 0 2ym filter (Millipore type FG) into preweighed cells that had been exhaustively rinsed with nearly dust-free water from a Millipore 4 stage purifier and dried Under vacuum, the samples were either concentrated or evaporated to dryness, depending respectively on whether a PBLG/DMF or PBLG/toluene sample was desired For... 

PBLG/toluene samples, toluene was added by weight via a 0.05im filter (Millipore type VM). The samples were then flame-sealed and homogenized by slow tumbling at room temperature (DMF) or 100 C (toluene). 

Reaction mixture 25 pi of freshly prepared 2 x reaction buffer, 15 pi of water, and 10 pi of filtered cell or tissue lysate (total volume of 50 pi). The reaction mixture is incubated for 30 min at 37°C in the dark, followed by adding 10 pi of oxidation solution. After oxidation for 30 min in the dark at room temperature, 10 pi of 1% ascorbic acid is added, mixed, and centrifuged for 20 min at 14,000 xg through a Micron 10,000 filter (Millipore, Ultracel YM-10). The filtrate is analyzed by HPLC (ideally only 20 pi of a 1 2 dilution with water are injected into the HPLC system). The starting lysate of 10 pi was diluted sevenfold. 

Collected air particles (1 g) are extracted twice with dichloromethane (100 mL) by either Soxhlet extraction (5-10 cycles/h for 16 h at 40 °C) or sonication (at room temperature for 15 min each time) (7). The dichloromethane extract is filtered through a 0.5-/xm filter (Millipore Corporation or equivalent) into a round-bottom evaporating flask and... 

Reagents. Organic solvents for HPLC separations—methylene chloride, methanol, isopropyl alcohol, hexane, and acetonitrile—were obtained as HPLC grade from Fisher Scientific. Type I water for HPLC and for the preparation of other aqueous solutions was purified as described previously (7). All HPLC solvents were filtered through a 0.45-/zm Millipore membrane filter (Millipore Corporation) and degassed... 

Freeze-drying. For a 7000-fold concentration, 70 L of drinking water was lyophilized in a Virtus Unitrap II. The dried residue was then divided into equal weights and packed into two columns (25 X 1.5 cm) with a sintered glass filter. The organic material was eluted consecutively with acetone, ether, and DMSO. The ether in the ether eluate was removed by rotary evaporation, and the dried residue was dissolved in DMSO. The DMSO concentrates were sterilized by filtration over a 0.2-/xm Teflon filter (Millipore). The acetone and DMSO concentrates were tested in the Ames test. 

Nucleic acids can be visualized by ethidium bromide staining, UV shadowing, or phosphorimaging of radioactive samples. A sterile scalpel should be used to excise the separated product which can then be eluted by electrophoresis (1 x Tris-borate, pH 8.3) into a 30kDa molecular weight cutoff (MWCO) filter (Millipore). The product is concentrated by centrifugation, dialyzed, and resuspended in the buffer of choice. The yield of nucleic acid is typically 75 %, and ethanol precipitation is not needed. 

Dilute the reaction mixture by adding 4 volumes of H20. Remove unreacted BMCC-biotin through a 30kDaMWCO filter (Millipore) by centrifugation for 8 min at 11 000 x g. Repeat this step to ensure that all unreacted BMCC has been removed before proceeding to the partitioning step (Section 8.3.6). 

Trypan Blue (Sigma-Aldrich), stock solution of 5 mg/mL in MilliQ water filtered using a 0.22 pm membrane filter (Millipore). 

FIGURE 6 (a) Centrifuge-tube membrane filter (Millipore Corporation), (b) The 96-well plate with membrane sealed to individual cavities with integral underdrain receptacles (Millipore Corporation). 

Different types of syringe filters were then evaluated to try to remove the problematic excipients. Figure 10.4c shows that the use of an Amicon Ultra-4 centrifugal filter (Millipore, Billerica, MA) removed the residual HPMC from the sample solution but did not remove the starch. The Amicon Ultra-4 filter, however, does introduce later eluting filter-related peaks that fortunately do not interfere with any components of interest. Starch was not removed by any of the filters tested. As a result, excipient placebo samples were used as part of the method. These placebo samples were extracted and injected onto the HPLC system to confirm which peaks in the fixed combination tablet samples were excipient-related and these peaks were not quantitated or reported as drug-related degradants. 

Soot from an 02-propane flame was produced in a 5 cm diameter 1-meter flow tube, with a total flow rate (N2 carrier gas) of 3.5 liter min. 1 0.2 pm pore size Fluoropore filters (Millipore Corp.) were used for mass evaluation. 

It consists of a 25-mm-diameter Deldrin filter holder (Gelman product No. 1109) with one of the nylon hose nipples removed. The filter used is a 25-mm-diameter, 0.5-pm pore size Fluoropore membrane filter (Millipore catalogue No. FHLP 025 00). An auto sampler cup cap is used to seal the apparatus, both before and after use. In use, the filter holder is attached to an Edwards E2 M12 vacuum pump. 

Note The purpose of the in line 1-pm filter is to retain any inorganic particles removed from the swab by the organic extraction. The filter and filter holder are an integral part of a subsequent concentration/cleanup procedure for inorganic FDR as outlined in reference 220. The filter unit consists of a 13-mm-diameter Swinnex disposable filter holder containing a 13-mm-diam-eter, 1-pm pore size, fluoropore membrane filter (Millipore FALP 01300). 

Yokohama, from May to November, 1985 are shown in Table IV. All samples were filtrated with a membrane filter (Millipore Type HA), and then the concentration of each ion and the pH values were measured. Rain water was sampled 16 times in 13 distinct rain events totaling 273 mm of precipitation. The pH value ranged between 3.7 and 4.8 with an average of 4.4. Concentrations of S(IV) and S(VI) were determined to be 0.8-23.5 pM and 6.8-84.4 pM, respectively. 

Mobile Phase Add 380 mL of acetonitrile and 10 mL of glacial acetic acid to 610 mL of glass-distilled water that has been filtered through a 0.45-p.m filter (Millipore, or equivalent). Mix, and de-gas thoroughly. 

Standard Solution Dissolve about 10 mg of Monoammonium Glycyrrhizinate Standard for analytical use (Sigma, or equivalent), accurately weighed, in 20 mL of a 1 1 (v/v) solution of acetonitrile water. Filter the solution through a 0.45- xm filter (Millipore, or equivalent). Prepare fresh daily. 

---