As a general rule, antigen-antibody reactions occur at a faster rate in low-ionic-strength solutions (LISS), which is why some blood banks use LISS instead of isotonic saline. The LISS used has an ionic strength of 0.03 mol/L (30 mmol/L) compared to isotonic saline, which has an ionic strength of 0.154 mol/L. At less than 0.03 mol/L, complement will attach to red cells non-specifically and cause false positives, so this is the minimum ionic strength that must be used in LISS solutions.
|
| Ionic Strength |