“…Plasma membrane integrity is one of the most commonly assessed sperm quality parameters for semen analysis in the honey bee, as the loss of integrity of this thin outer boundary layer is considered incompatible with sperm viability [ 100 ]. Methods to assess the plasmalemma status are based on the increased permeability of damaged membranes to different substances, such as stains [ 57 , 69 , 93 , 101 ] or fluorescent probes [ 6 , 9 , 11 , 12 , 18 , 20 , 22 , 23 , 28 , 52 , 64 , 67 , 71 , 72 , 89 , 94 , 95 , 102 , 103 , 104 ]. The most commonly used fluorochrome for staining dead sperm cells is propidium iodide (PI).…”