Serological pipet

Volumetric transfer pipets Measuring and serological pipets ... 

Beakers 10 to 1000-ml. volumetric flasks 1-ml. volumetric pipet, serological pipet steam bath vacuum desiccator vacuum pump and water aspirator are also required. 

FIGURE4.il The tips of two styles of measuring pipets. The Mohr pipet is shown on the left, and the serological pipet on the right. The graduation lines on the Mohr pipet stop short of the tip, but on the serological pipet, pass through the tip. 

Disposable serological pipets are available. They are termed disposable because the calibration lines are not necessarily permanently affixed to the outside wall of the pipet. The calibration process is thus less expensive, resulting in a less expensive product that can be discarded after use. 

With a Mohr pipet, the meniscus must be read twice, but with a serological pipet, the meniscus may be read only once, if desired. Explain this. 

The serological pipet is calibrated through the tip and may be used by adjusting the meniscus to the line that would deliver the desired volume by letting it drain completely (and blowing it out). The Mohr pipet is calibrated only to the lowest calibration line and cannot be drained below this line. 

If I chose a Mohr pipet, it would not be calibrated for blowout. If I chose a serological pipet, it would be calibrated for blowout. A blowout pipet would have one or two frosted rings completely circumscribing the top of the pipet. See Figure 4.12 for details on how to make the delivery. 

The milliliters of 1000 ppm needed is pipetted into separate 50-mL volumetric flasks and water is added to each to the 50-mL mark. Each flask is then shaken to make the solutions homogeneous. The pipet needed would be a small serological pipet, perhaps 0.50 mL in capacity. Alternatively, a micropipet, such as described in Chapter 4, can be used. 

H Serological pipet courtesy of VWR Scientific, Division of Univar. 

Serological pipets (Figure 1.4H) are similar to Mohr pipets, except that they are graduated downward to the very tip and are designed for blow-out. Their use is identical to that of a Mohr pipet except that the last bit of solution remaining in the tip must be forced out into the receiving container with a rubber bulb. This final blow-out should be done after 15 to 20 seconds of draining. 

Pipettor pump courtesy of Cole-Parmer Instrument Co E Pasteur pipet courtesy of VWR Scientific, Division of Univar F Volumetric pipet courtesy of VWR Scientific, Division of Univar 6 Mohr pipet courtesy of VWR Scientific, Division of Univar H Serological pipet courtesy of VWR Scientific, Division of Univar... 

A modified Neubauer hemocytometer was used at 40x magnification to obtain the number and size range of gel spheres in suspension. The depth of the counting chamber was increased from the usual 0.1 mm for routine cell counting to 0.3 mm to ensure unrestricted influx of the larger gel particles. A well-shaken 1 1 (v/v) suspension of pre-swelled gel spheres in PBS was diluted 5-fold and sampled with a 1-ml plastic serological pipet (Falcon, Oxnard,... 

Disposable serological pipets, 10 mL for preparation of the carbon column specified in Section 9.10. 

The quality of apparatus is crucial. The quality of the pipets directly affects the reliability of the analytical information. It is necessary to use measuring pipets of high quality for reliable measures of volume, e.g., clinical, serological pipets, micropipets, syringe pipets. Syringe pipets must be used for measurement of microliter volumes. In volumetric analysis more reliable burets are necessary. For small quantities of sample, micro- and ultramicro-micrometer burets are recommended. Only well-calibrated pipets and burets will assure the accuracy of volume determination. 

Disposable Serological Pipets (National Brand) Plastic, sterile, cotton-plugged. 

Sericin (Seidengununi/Seidenleim) serological pipet serologische Pipette serum (p/ sera or serums)... 

---