Returning later to investigate, the co-worker discovered a wash bottle and testing vials full of radioactive chromium 51--a substance that should not have been present in the vials until days later in the experiment.
Urine (400 μl) was pipetted into 10 ml Exetainer gas testing vials (Labco, High Wycombe, Berks); glass inserts (200 μl, Chromacol, Welwyn Garden City, Herts) containing platinum catalyst (platinum 5% on alumina powder, 325 surface area >250 m g−1, Sigma Aldrich, Gillingham, Dorset) were added to each vial, taking care not to wet the catalyst.
To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (−88°C to −93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen.
This scan shows our lowest tested vial sediment activity of 3.5 MBq (≈3 MBq/ml).
The biopsy was placed in a test vial, incubated at 37°C and read within 24 h.
Three to ten milligrams of substance were scraped into a test vial and weighed with an analytical balance.
In each trial, up to 15 random pairs of males were transferred into a 50 ml test vial (2 males/vial).
Nematode-suspension (0.5 ml, 20,000 individuals) was transferred to each test vial and the test organisms exposed for 48 h to the respective treatment.
Single females were allowed to acclimate to their test vial for 24 hours before a single male was introduced by aspiration.
For EXTEM, 20 μL of 0.2 mol/L CaCl2 (star-tem™) and 20 μL of human recombinant tissue factor (r EXTEM™) were added to a test vial.
Because these common buffers are strongly dependent on temperature, the final pH was verified by measurement at 30 °C for a test vial with all components.
