| All assays were made in triplicate and possible interference with cross-reactive substances was checked by analysing a range of dilutions. |
| Further dilutions only serve to reduce our chance of finding an arsenic ion by an order of magnitude each time. |
| Cells from new zygotic colonies were resuspended in 1 ml water and appropriate dilutions were made. |
| Secondary antibodies, dilutions, and mounting conditions were as described above. |
| Four fivefold serial dilutions were performed to produce samples of 0.2 ml each. |
| Serial dilutions of the test solutions with culture medium were prepared before in vitro assay. |
