The detection of PD-1 should not be carried out too long after all of the laboratory procedure steps have been completed. If samples are stored at 4℃ away from light, the detection time should be limited to 8 hours; if stored at room temperature away from light, the detection time should be limited to 4 hours. This is to ensure the accuracy and stability of the detection results.
Li et al. (Thu,) studied this question.