To discuss the effects of sample storage time and temperature on lymphocyte subsets detected by flow cytometry.

Use flow cytometry to detect lymphocyte subsets of a total of 53 blood samples from hospitalized and out-patient patients in Qinghai Provincial People′s Hospital from October 26, 2018 to March 30, 2019. The test was completed within 4 hours after sample collection, which is the control group. The treatment groups are as follows: pretreatment was completed within 4 hours and detected after saving samples at room temperature (group A) for 24 and 36 hours; the tests were performed after keeping samples at room temperature (group B) for 24, 48, 72 hours; completed detection after preserving samples in 4 ℃ condition (group C) for 24, 48, 72 hours.

In treatment group A, there was no significant difference in the results of lymphocyte subsets detected after 24 hours of storage compared with the control group(P>0.05); after 36 h of storage, CD3+and CD3+CD8+T lymphocytes percentages were significantly increased [(74.28±11.31)% vs (73.78±11.33)%, (32.15±14.82)% vs (31.00±14.79)%; all P<0.05], while CD19+cells percentage were markedly decreased [(15.60±12.23)% vs (16.11±12.38)%; P<0.05]. In group B, compared with the control group, there was no obvious change in lymphocyte subsets tested after 24 hours(P>0.05); after 48 hours of storage, CD19+cells percentage were observably reduced [(15.60±12.09)% vs (16.11±12.38)%; P<0.05], while other results showed no obvious change (P>0.05); after 72 hours of storage, CD3+and CD3+CD8+T cells percentages elevated significantly [(75.78±11.18)% vs (73.78±11.33)%, (32.57±14.90)% vs (31.00±14.79)%; all P<0.05], and CD19+cells percentage decreased markedly [(14.89±11.92)% vs (16.11±12.38)%; P<0.05]. In group C, there also was no significant change in the results between detecting after 24 hours and the control group(P>0.05); after 48 hours of storage, CD3+CD8+T cells percentage elevated obviously [(32.03±14.95)% vs (31.00±14.79)%; P<0.05] and CD19+cells percentage decreased markedly [(15.32±11.97)% vs (16.11±12.38)%; P<0.05]; after 72 hours of storage, CD3+and CD3+CD8+T cells percentages were significantly increased [(75.63±11.08)% vs (73.78±11.33)%, (32.62±14.98)% vs (31.00±14.79)%; all P<0.05], while CD56+and CD19+cells percentages were reduced observably [(8.21±6.52)% vs (9.02±6.80)%, (14.83±11.79)% vs (16.11±12.38)%; all P<0.05].

The blood samples can be kept at room temperature and the testshould be completed within 48 h if the detection of lymphocyte subsets by flow cytometry cannot be performed in time; for the samples that have been pretreated, detection can be completed after saving at room temperature for 24 h, and the above treatments had no significant effect on the inspection results.

Lymphocyte subsets; Flow cytometry; Sample preservation