Table 3 Summary of non-biological carriers (vitrification devices) and cryoprotectants

Cryoloops

Test yolk buffer (TYB) with 12% v/v glycerol (Irvine Scientific, USA) [29].

With or without glycerol. Test-egg yolk-glycerol (TEYG) freezing medium (Scandinavian IVF Science, Gothenburg, Sweden) (glycerol concentration 12%); Standard medium (no cryoprotectant) [55].

A 50:50 mixture of HTF-HEPES with 6% plasmanate and the TYB–glycerol (Irvine Scientific, USA) cryoprotectant [30].

A 50:50 mixture of TYB–glycerol (Irvine Scientific, USA) and m-HTF medium supplemented with 6% Plasmanate [31].

Culture dish

A 50:50 mixture of IVF-20 medium (JCD, France) and sperm freezing medium (Medicult, Denmark) [33].

Sperm freezing medium (Medicult, Denmark) [34].

Cell Sleeper

A mixture of 0.7 mL SpermFreeze (FertiPro, Belguim) and 1.0 mL HFF99 (Fuso Pharmaceutical Industries, Japan) containing 20% serum substitute supplement (SSS) (Irvine Scientific, USA) [35].

SpermFreeze (FertiPro, Belgium) containing 20% SSS (Irvine Scientific, USA) [36].

A 50:50 mixture of SpermFreeze solution (Vitrolife, Goteborg, Sweden) and human serum albumin (HSA) supplemented (10 mg ml^− 1, by manufacturer) Sydney IVF Gamete Buffer (Cook Medical) [37].

Cryotop

A mixture of 0.7 mL SpermFreeze (FertiPro, Belguim) and 1.0 mL HFF99 (Fuso Pharmaceutical Industries, Japan) containing 20% SSS (Irvine Scientific, USA) [35].

With or without glycerol. Two different cryoprotectants, sucrose (Sigma, USA) and SpermFreeze (FertiPro, Belguim) were tested. SpermFreeze includes both glycerol and sucrose. The sucrose-based freezing medium was 0.1 M sucrose in HFF99 (Fuso Pharmaceutical Industries, Japan) containing 20% SSS (Irvine Scientific, USA). SpermFreeze-based freezing medium was a mixture of SpermFreeze (0.7 mL) and HFF99 (1.0 mL) containing 20% SSS [38].

Cryoleaf

12% (v/v) glycerol and 20% (v/v) egg yolk in 0.1 M citrate buffer (PH = 7.2) [39].

Cryopiece

Freezing medium used [40].

Closed slice

With or without cryoprotectant. A 50:50 mixture of commercial sperm cryoprotectant (Quinn’s Advantage SAGE, USA) and HEPES buffer with 10% HSA. The without cryoprotectant group used HEPES buffer with 10% HSA [41].

HEPES buffer with 10% HSA [42].

The novel sperm vitrification device

A 50:50 mixture of Quinn’s Advantage Sperm Freezing Medium (SAGE, USA) and Quinn’s Sperm Washing Medium [43].