Platelet preservation. I. The use of decrease in light absorbance as a screening method in cryopreservation studies on human platelets

Measurement of Transmitted Light as an Indicator of Cryopreserved Platelet Viability

“…The initial dispersion of the mea sured parameters observed with F platelets has already been pointed out by Fratantoni et al [6] and Holme et al [8], In this study trans mitted light was used to describe the behavior of C platelets in a motionless environment. Odink and Sprokholt [17] have used light absorbance as an indicator of cryopreserved platelet function: although, they described it as a useful tool, they did not indicate the limi tations of the assay. log(T) was linearly related to morphology and HSR, and therefore, it shows that this method is a valid indicator to report platelet quality.…”

“…Transmittance of the PC was read on a spectrophotometer (Lambda 4A, Perkin-Elmer) at the wavelength of 610 nm [17,23]. The measurements were read at room temperature (21°C) against the autologous plasma of the unit.…”

“…For example, detection of shape change in a C platelet population by the Holme technique is complex as freezing re duces the number of discs. Nevertheless, opti cal measurements have been shown valuable techniques to allow comparison of platelet viability after freezing in the presence of dif ferent cryoprotectants [17], and to monitor the permeation of cryoprotectants in platelets [20], It was previously reported that C plate lets have a significantly higher transmittance than fresh (F) ones [17, unpubl. observation].…”

“…Methods like photometry have been used in the characterization of platelet shape change (disc to sphere transfor mation) [5][6][7][8][9][10][11], abnormality [12,13], mem brane deterioration [14] or size [15,16]; these methods are based on light transmission and light scattering properties of platelet samples. Shape and volume are primarily detected by scattered light when the cells are in motion [7], whereas granularity can be detected in a static population [17], Fratantoni et al [6], Jaremo et al [9] and Bcllhouse et al [18] have attempted to quantify the quality of whole fresh platelet concentrates using light scatter ing measurements but other investigators were not able to reproduce these results ade quately [19]. Holme and Murphy [7] have developed a method to quantify the disc to sphere transformation.…”

Platelet Freezing for Serological Purposes with and without a Cryopreservative

“…To 1-2 x 109 platelets, suspended in 0.5 ml autologous plasma or plasma from a donor with blood group AB (AB plasma), 0.5 ml 10% (v/v) DMSO (diluted in autologous or AB plasma) was added dropwise under constant stirring just before the freezing procedure. Straws filled with 1 ml of this platelet mixture were frozen according to a con trolled cooling programme, as described by Odink and Sprokholt [14] and stored in liquid nitrogen. Thawing was performed by incubating the straws with the frozen platelets in a waterbath of 37 "C. Just after thawing, the platelet suspension was diluted in 4 ml autologous or AB plasma to which 10% (v/v) of 2% (w/v) sodium-EDTA-containing phosphate buffer saline (EDTA-PBS) was added to a final DMSO concentration of 1% (v/v).…”