TABLE 2.
Effects of storage conditions on CP hemolytic activity
| Blood samplesa | Storage temp (°C) | Storage time (days) | No. of samples | Mean CP activity (%) | Mean % difference in CP activity ±SEMb |
|---|---|---|---|---|---|
| Control EDTA-plasma | −70 | 10 | 77 | ||
| EDTA-plasma | +4 | 1 | 10 | 77 | 0.5 ± 0.9 |
| Control EDTA-plasma | −70 | 10 | 77 | ||
| EDTA-plasma | +4 | 2 | 10 | 75 | 1.5 ± 1.0 |
| Control EDTA-plasma | −70 | 22 | 91 | ||
| EDTA-blood | +22 | 1 | 22 | 92 | 1.4 ± 2.1 |
| Control EDTA-plasma | −70 | 5 | 111 | ||
| EDTA-blood | +22 | 2 | 5 | 95 | 16.4 ± 6.1 |
| Control EDTA-plasma | −70 | 5 | 97 | ||
| EDTA-blood | +22 | 3 | 5 | 80 | 17.4 ± 12.4 |
a
Samples of EDTA-blood were collected from SLE patients (n = 52), and each sample was divided into two aliquots, one of which was frozen immediately after being harvested (control EDTA-plasma) and one of which was stored either at 22°C (EDTA-blood) or at 4°C (EDTA-plasma). Prior to analysis, the samples were transferred to Veronal-buffered saline containing lepirudin as described in Materials and Methods, and the samples from each patient were analyzed in parallel in the CP hemolytic assay. The difference in recorded CP activities between samples from the same individual was calculated.
b
None of the differences was statistically significant.