Abstract
Purpose: :
To evaluate 25 Gauge and 20 Gauge Vitrectomy on flow cytometry based cell viability and diagnostic yield using human Burkitts lymphoma cells in suspension.
Methods: :
Cultured human Burkitts Lymphoma cells were characterized for cell surface markers prior to use. Five groups (25-gauge at 600 cut-per-minute (cpm) and 1500 cpm, 20-gauge at both speeds, and a control) contained two samples of 3 ml suspensions of lymphoma cells in RPMI media at concentrations ranging from 1 to 9 x 10^6. Two samples from each group were vitrectomized using the Alcon 25 G and 20 G systems at 600 cpm and 1500 cpm. Constant, manual aspiration was performed using a 10ml syringe drawn back to the 5ml mark. Control samples were extracted using 18-G needles without vitrectomy. All samples were placed in fresh RPMI media and transported to the pathology lab with standard flow cytometry performed the same day. Antibodies for CD 45 and CD 19 were used for tumor cell identification, and 7-Amino-actinomycin D (7-AAD) dye was used for measuring cell viability.
Results: :
The mean cell viability was 90.1 % and 79.7 % for the non-vitrectomized and vitrectomized groups, respectively. Cell viability was significantly higher in the 25 G vitrectomy group when compared to 20 G vitrectomy at both cut rates (p<0.05). The non-vitrectomy group had higher cell viability compared to 25 G vitrectomy at 600 cmp (p=0.02), but not significantly higher from 25 G vitrectomy at 1500 cpm (p=0.11). Percentage of cells positive for CD 45 and CD 19 was not statistically different between any of the 5 groups. A high K:L (>90:1) was seen in all 5 groups.
Keywords: retina • pathology: experimental • cell survival