Serological pipette

Pipettes and Petri Dishes. It is preferable to use presterilized disposable pipettes and petri dishes. They are not only more economical to use, but the method of sterilizing and sealing is generally better than that accomplished in most laboratories. Pipettes should be 1 ml serological type graduated in 0.1 ml. If concentrates are to be sampled, the large bore pipette for viscous liquids should be specified. Petri dishes should be standard 100 x 15 mm. 

Burette 0.03 mL Serological pipette (only Class B lower)... 

There are three types of volumetric pipettes volumetric transfer, measuring, and serological. The differences are based on whether the volume within the pipette is subdivided and if the volume in the tip is included in the calibration (see Fig. 2.19). 

Measuring pipettes come in both Class A and Class B and are available in two styles Style 1 is a standard taper tip, and Style 2 is a long taper tip (Class B only). Serological pipettes are only made to Class B tolerances and have no special styles. Volumes, tolerances, and other data of measuring pipettes are provided in Table 2.17. Information for serological pipettes is provided in Table 2.18. All calibrations were made at 20°C. 

From ASTM Tables E 714 (Standard Specification for Disposable Glass Serological Pipettes), Table 2 (omitted was the column titled Coefficient of Variation ), and E 934 (Standard Specification for Serological Pipette, Disposable Plastic), Table 2 [omitted was the column titled Coefficient of Variation (Equal to or less than 1.5%) ]. Reprinted with permission. 

To fill a measuring or serological pipette, draw the solution to just above the volumetric level, then let the solution fall to the calibration mark. Remove the pipette from where you drew the fluid, and wipe the tip with a laboratory tissue to remove any excess solution from the outside of the pipette so that it is not included with the calibrated liquid. 

There are three different styles of serological pipettes. Style I has a standard end piece. Style II has an end that can receive a cotton plug (see Fig. 2.20). Style III has the same type of end as Style II, but also has a larger tip opening to speed the emptying process. 

Pipettes are also made as disposable serological pipettes. They are just as easy to use as regular pipettes and are typically made out of plastics or soda-lime glass. They have very low-quality standards, and their calibrations are not required to have the same permanency as regular pipettes. Thus, if you try to wash them, the... 

Use a serological pipette to remove the chloroplasts from the 30 to 50% sucrose interface. Do not include any aggregates adhering to the wall of the centrifuge tube. The nuclei pellet through the 50% sucrose layer and can be separately recovered from the bottom of the tube. 

Sephadex G-50 column. Add 20 ml of phosphate buffer to 1 g of Se-phadex G-50 Fine. Let stand at least 3 hr at room temperature, then pour the slurry into a 10-ml disposable glass serological pipette containing a small amount of glass wool at the tip. The bed volume should be about 10 ml. 

A transfer pipette is designed to transfer a known volume of liquid. Measuring and serological pipettes are scored in units such that any volume up to a maximum capacity is delivered. Table 1-12 shows examples of tolerances of various types of these pipettes. 

Figure 1-1 Pipettes. A,Volumetric (transfer). B, Ostwald-Folin (transfer). C, Mohr (measuring), D, Serological (graduated to the tip).

With graduated pipettes, the flow of liquid may have to be slowed during delivery. Serological pipettes are calibrated to the tip, and the etched glass ring on top of the pipette signifies that it is to be blown out. The pipette is first allowed to drain, and then the remaining liquid is blown out. 

Separation of RNase T2 digests of 52p-labeled polio virion RNA (a) mRNA (b) and replicative intermediate ENA (c) on DEAE-cellulose in the presence of marker nucleotides. Columns were in 5 i al plastic pipettes (Falcon, Serological) elution with triethylammonium acetate, pH 5, was as described (5, 111 12). 

Apply the clarified crude lysate (Subheading 3.1.2, step 3) onto the column using a 10 mL serological pipette see Note 18). Collect the flow-through in a new mbe that is kept on ice. Once the lysate has been loaded onto the top of the resin bed, adjust the flow rate to 2 mL/min Note 19). When the majority of the lysate has passed through the column, close the stopcock valve. Pass the lysate over the column two more times in the same manner just described. 

Pipettes ated serological pipette. These glass pipettes are available commercially in a num-... 

Add 30 ml 1.0 M sorbitol. Very gently invert the tube to resuspend the spheroplasts. If necessary, aid resuspension by gently pipetting with a 50-ml serological pipette. Add 20 ml 1.0 sorbitol and mix by gentle inversion. 

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

---