Laminar-flow clean bench

Vertical laminar flow clean benches also are not BSCs. They may be useful, for example, in hospital pharmacies when a clean area is needed. Although these units generally have a sash, the air is usually discharged into the room under the sash, resulting in the same potential problems as the horizontal laminar flow clean benches. 

Chemical preconcentration of the samples (e.g., extraction into chloroform and dithizone) was used in the past by several authors in order to determine the very low concentration of Pb in ancient Antarctic ice (6, 45, 64). Although this method gave reliable results, it needed a huge amount of sample (500-1000 g) and a long period of sample treatment with organic solvents. Another method is based on the preconcentration onto W wire loops that can be placed directly in a graphite furnace of instrument AAS for the atomisation of adsorbed metals for the analysis (44, 65). To minimise the contamination problems from the air of the laboratory the whole preconcentration procedure was carried out inside a vertical laminar flow clean bench. Detection limits of 0.01, 0.47, 0.22 and 0.24 pg/g were obtained for Cd, Cu, Pb and Zn respectively (44). These extremely low detection limits have recently enabled the concentrations of heavy metals in Antarctic ancient ice and recent snow to be determined (28, 72). 

For Cd, laminar flow clean benches or clean rooms were recommended to avoid contamination. Acids used should be further purified by sub-boiling point distillation. If all precautions to reduce blanks are not followed too high results will be observed. 

All operations (cleaning, filtration, acidification and sample handling) were carried out in a specially designed Class 100 room, either fitted in a standard 20 ft transport container which was fully equipped as a chemical laboratory or in a room transformed as such on board of the research ship. All operations with the sample were performed in a closed system, except for the sample acidification and the filling of the bottles, which were performed in a laminar flow clean bench inside the clean room. All personnel working in the clean area used polythene gloves, dust-free garments and shoe-covers. 

Possible contamination due to atmospheric dust and particle emission attributable to laboratory staff activities (smoking, use of cosmetics, etc.) can be avoided in trace analytical determinations at the pg/kg, pg/L, and pg/m ranges by working under clean-room conditions. A laminar-flow clean bench ensures that particles with a diameter >0.1 pm will be removed with an efficiency of 99.9% through high-efficiency, sub-... 

Baker Company. 9 5. Biological Safety Cab-inets. Laminar Flow Clean Benches and Equipment Catalog. The Baker Company, Sanford, ME. 

Horizontal laminar flow clean air benches are not BSCs (Section 10.3.4). They discharge HEPA-filtered air across the work surface and toward the user. These devices only provide product protection. They can be used for certain dean activirie.s, such as the dust-free assembly of sterile equipment or electronic devices. These benches should never be used when handling potentially infectious materials. The worker can be exposed to materials on the clean bench. Horizontal clean air benches should never be used as a substitute for, i biological safety cabinet. 

Vertical Laminar Flow Vertical Flow Biological Clean Bench Safety Cabinet... 

Flow photolysis experiments are carried out in microfluidic channels see Note 7). We use soft lithography (14, 19), a well-established polymer molding procedure, to build our microdevices. The following steps are carried out in the clean and dry environment of a laminar flow bench. 

As the construction and maintenance of a clean room requires a huge capital investment, it is also possible to do the processing of CP microfabrication using other means of providing a contamination controlled environment, such as laminar flow benches with HEPA filters. 

Exogenous sources such as a person s hair or skin, doorknobs, laboratory benches, dust, reagents, thermal cyclers, and pipet tips are some of the common sources of DNA contamination. Ideally, a laminar air flow bench with filtered air provides a clean, dust-free environment. Sample preparation should be done in a separate room or area. The addition of sample to the PCR reaction mixture in the... 

Flow regime, laminar A constant and directional flow of fluid across a clean workbench. The flow is usually parallel to the surface of the bench. 

---