A sperm cryopreservation protocol requiring dimethylacetamide (DMA, 6%) as a cryoprotectant was optimized via assays involving different prefreezing equilibration times (1, 10, 30, 60, and 120 min at 5°C) and different freezing rates achieved by the following: 1) using nitrogen vapor to reduce the temperature from 5°C to -85°C at 10°C/min (slow freezing rate); 2) using a biological freezer unit...

The techniques of cryopreservation let embryos which cannot be immediately transferred to the patient be stored for future use. The first successful pregnancy after transfer of cryopreserved human embryos was described in 1983 by Trounson et al. and the first birth after cryopreservation was later reported in 1984 by Zeilmaker et al.). The technique has rapidly been applied in most in-vitro fer...

Vitrification and slow-freezing methods have been used for the cryopreservation of human pluripotent stem cells (hPSCs). Vitrification requires considerable skill and post-thaw recovery is low. Furthermore, it is not suitable for cryopreservation of large numbers of hPSCs. While slow-freezing methods for hPSCs are easy to perform, they are usually preceded by a complicated cell dissociation pro...

Secondary hyphae of Lyophyllum ulmarium were shown to tolerate slow freezing, which allowed extracellular freezing, to -196 degrees C. A freeze-fracture study showed that under this non-lethal freezing condition, the plasma membrane of the secondary hyphae did not show any ultrastructural changes as compared with the control, except gross cellular shrinkage. Tertiary hyphae of Lyophyllum ulmari...

The ability to spur growth of early stage gametic cells recovered from neonates could lead to significant advances in rescuing the genomes of rare genotypes or endangered species that die unexpectedly. The purpose of this study was to determine, for the first time, the ability of two substantially different cryopreservation approaches, slow freezing versus vitrification, to preserve testicular ...

Suspensions of leukemic cells of mice from three different strains of leukemia were subjected to rapid or slow freezing and rapid or slow thawing. Suspensions rapidly frozen to -196 degrees C. were in all cases innocuous, whereas those frozen slowly were capable of transmitting leukemia. The infectivity of slowly frozen material varied from an estimated 0.0001 per cent to 1 per cent of that of ...

BACKGROUND This study aimed to investigate the effects of vitrification and slow freezing on actin, tubulin, and nuclei of in vivo preimplantation murine embryos at various developmental stages using a Confocal Laser Scanning Microscope (CLSM). MATERIAL/METHODS Fifty female mice, aged 4-6 weeks, were used in this study. Animals were superovulated, cohabitated overnight, and sacrificed. Fallop...