Counting vial

The supemate thus obtained containing unbound chlordiazepoxide-14C is decanted into a counting vial and toluene is added, and... 

The irradiated coal sample, mixed with Alundum in a porcelain boat containing bromide carrier, is burned in the same manner as in the method for mercury (4), and the combustion products are trapped in two sodium or potassium hydroxide solutions. The alkali solution, in a large counting vial, is counted directly for the 0.56 MeV y-ray photopeak of 36-hr 82Br. 

If the available scintillation counter does not have an adequate quench correction function, it may be necessary to process a non-radioactive fecal sample as described above and add an equivalent amount of the hexane extract to the counting vials for the starting sterol mix (from Section 2.1 or 2.2 above) so it is quenched similarly to the fecal samples. 

As shown in Figure 3, our detectors came equipped with a cylindrical plastic cell about the size and shape of a scintillation counting vial into which a U-shaped tube had been drilled. When this cell has been packed with scintillation grade anthracene a flow cell quite satisfactory for aqueous systems is obtained. 

An alternative method which can also be automated by the use of the Titertek supernatant harvester (see Appendix 3) involves the measurement of radioactive chromium released into the culture medium from killed cells. The harvester consists of a set of absorbent cylinders aligned so that they may be inserted into the wells of a microtitration plate (Appendix 3). Once the supernatant in the wells has been absorbed the cylinders are transferred to counting vials and the amount of radioactive chromium released from the cell monolayer is estimated. Cells take up 51 Cr sodium chromate rapidly and the excess is readily washed away by rinsing in culture medium. 

An aliquot of the distilled and condensed tritium-containing water sample is prepared for LS counting by adding it to an LS cocktail in a counting vial. Also counted in the same batch are two other vials with scintillation cocktail, one with a standard tritium solution, and the other with a blank water solution. 

Step 3. Cool the sample to room temperature. Transfer an aliquot with a 10-mL pipette to a clean scintillation counting vial. 

Step 11. Elute the strontium from the column with two 5-mL portions of 0.5 M HN03. Collect the two eluents in a clean plastic container (a 20-mL liquid scintillation counting vial or a 50-mL centrifuge tube is suitable). 

Other materials were human albumin fraction V (Sigma Chemical Company), Merthiolate (British Drug House), Sephadex LH-20 and Sephadex G-25 fine (AB Pharmacia, Sweden), Insta-Gel (Packard Instrument Company, U.S.A.), counting vials of polyethylene (Scintitec La-boratorieudstyr A/S, Denmark). 

At equilibrium the mixtures are diluted and passed through a 0.45 fim Millipore filter. The filter is then washed and dissolved in a counting vial. 

Total count = (total count vial - background vial count) x 4% hybridization... 

Finally, elute the [ PjcAMP by adding 3 ml of 100 mM imidazole, pH 7.5, to the alumina columns and allow them to drip directly into 7-ml scintillation counting vials. Cap the scintillation vials and count using the P window of the scintillation counter for 1 min. 

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