Calibrated automatic pipets should be used on specimens that require a dilution. Mouth pipetting must of course always be avoided.
Automated cell counters may not be the best choice for cell counts on CSF because of the variation in background counts.
A high background count could cause a false increase in normal or slightly elevated count. The dilution required is based on the appearance of the sample.
| Appearance | Dilution Ratio | Volume of Sample | Volume of Diluent |
| slightly hazy | 1:10 | 30 ul | 270 ul |
| hazy | 1:20 | 30 ul | 570 ul |
| slightly cloudy | 1:100 | 30 ul | 2970 ul |
| slightly bloody | 1:100 | 30 ul | 2970 ul |
| cloudy | 1:200 | 30 ul | 5970 ul |
| bloody | 1:200 | 30 ul | 5970 ul |
| turbid | 1:10000 | 0.1 ml of a 1:100 dilution | 9.9 ml |
