Pipetting devices

Nuremberg, Numbers I589-I6I5, 279-292 (1975)], is essentially a centrifugal pipet device. Size distributions are calculated from the measured solids concentrations of a series of samples withdrawn through a central drainage pillar at various time intervals. 

Several methods have been used for the matrix application (1) immersing a tissue section quickly in a matrix solution, (2) spraying matrix solution onto a tissue section with an air brush, (3) putting small droplets of matrix solution onto a tissue section with an automatic pipetting device that can dispense picoliter volumes (lpL = 10 pk) of reagents.4,5,715161819... 

FIGURE 4.17 Atypical commercial pipetting device. The close-up on the right shows that it is dialed in to deliver 500 ftL, or 0.5 mL. 

FIGURE 4 Pipetting devices Eppendorf pipettes, Eppendorf EDOS 5222 electronic dispensing system, PerkinElmer Packard MultiProbe II EX and Tomtec Quadra 3 96-well plate liquid handling system. 

Although most quantitative transfers are now done with automatic pipetting devices, which are described later in the chapter, instructions will be... 

Pipet bulbs, or battery-operated pipetting devices—e.g., Pipet-Aid (Drummond Scientific)... 

Seligson, D., An automatic pipetting device and its application in the clinical laboratory. Am. J. Clin. Pathol. 28, 200-207 (1957) see also Seligson, D., and Marino, J., Automatic pipetting attachment for the Van Slyke manometric apparatus for C02 determination. Clin. Chem. 4, 120-126 (1958). 

Lood should be stored in cabinets or refrigerators designated for such use only. Mechanical pipetting devices should be used and mouth pipetting prohibited. All hazardous chemicals should be used in a chemical fume hood. 

Mouth pipeting is prohibited mechanical pipeting devices are used. 

As manual, multichannel pipeting devices and plate-based detection systems became staple tools in the modem discovery laboratory, bioassays for moderate throughput have been developed in a wide variety of formats. The flexibility of these detection devices allowed assays that utilize visible-, fluorescence-, luminescence-, and radioactive-based readouts. Manual pi-... 

No mouth pipetting - ose automatic pipettes or pipetting devices. 

The second type of false-positive result can occur at the detection stage, e.g., when the liquid-transfer device pipets a strong positive sample followed by a negative sample. Because a typical PCR reaction can produce 10 -1012 molecules of amplified DNA in a 100-pl reaction and a radioactive probe can detect about 107 molecules, it is necessary to limit liquid carryover to less than 0.001-0.01 pi (Table 2). Such levels are possible with available automated pipeting devices, but manual pipeting should employ positive-displacement pipets or tips that prevent aerosols from contaminating the device. 

Pipets are filled by suction, using a rubber pipet bulb, a pipet pump, or other such pipetting device. Before using a pipet, practice filling it with water. No solution should be pipetted by mouth. 

Mouth pipetting is prohibited mechanical pipetting devices are to be used. 

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