Plateletpheresis with the COBE spectra single needle access option. 
A group of modifications, including a reservoir bag in the return circuit, has been devised to allow single needle plateletpheresis with the COBE Spectra.  We compared the number and quality of platelets collected from 10 subjects in paired donations with single and dual needle protocols.  There was no evidence of hemolysis with either protocol.  Mean (+/- SD) platelet yields were 3.61 +/- 1.47 x 10(11) with two needles and 3.31 +/- 1.31 x 10(11) with the single needle procedure (P = .13).  Mean leukocyte levels (standard manual counting chamber) were 1.0 +/- 1.7 x 10(7) and 1.2 +/- 1.0 x 10(7), respectively (p = .78).  pH values during storage were acceptable in both groups of concentrates, and there were no significant differences between the single needle and dual needle concentrates in morphology scores or beta-thromboglobulin levels at 0, 1, 3, or 5 days of storage.  Thus the single needle modification produced platelets that were comparable in quantity and quality to those from the standard dual needle plateletpheresis protocol.