Mammalian spermatozoa experience osmotic stress when the glycerol is added to the cells before freezing and removal from the cells after thawing. To minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving bull spermatozoa. The primary goal of this stud...

BACKGROUND Sperm vitrification is a technique of ice and cryoprotectant free cryopreservation by direct plunging of sperm suspension into liquid nitrogen (LN2). The aim of this study was to investigate the influence of cryoprotectant free-vitrification on human sperm fine structure by MSOME technology and the fertility potential by zona binding assay (ZBA). METHODS 20 normo-ejaculates were pr...

Successful cryopreservation of most multicompartmental biological systems has not been achieved. One prerequisite for success is quantitative information on cryoprotectant permeation into and amongst the compartments. This report describes direct measurements of cryoprotectant permeation into a multicompartmental system using chemical shift selective magnetic resonance (MR) microscopy and MR sp...

The deleterious effects of three cryoprotectants, glycerol, dimethylsulfoxide (DMSO), and dimethylacetamide (DMA), were compared on fowl spermatozoa. The viability and integrity of spermatozoa were measured with eosin-nigrosin smears. Glycerol was the least deleterious cryoprotectant, followed by DMA, and DMSO was the most toxic. Methods employing either glycerol or DMA were then compared for t...

We investigated the ecological physiology and behavior of free-living wood frogs [Lithobates (Rana) sylvaticus] overwintering in Interior Alaska by tracking animals into natural hibernacula, recording microclimate, and determining frog survival in spring. We measured cryoprotectant (glucose) concentrations and identified the presence of antifreeze glycolipids in tissues from subsamples of natur...

INTRODUCTIONA pre-embedding method of immunochemical staining is used if antigens are damaged by resin embedding, or if the best preservation of membranes is required. Applying immunogold reagents to sections of lightly fixed tissue, free of embedding medium, can be a very sensitive method of immunochemical staining. Cells or tissues are fixed as strongly as possible and then treated with a cry...

In spring, the lowest temperature during freezing that can be survived by wood frogs (Rana sylvatica) from southern Ohio is approximately -3 degrees C. We investigated whether the thermal limit of freeze tolerance in these frogs is regulated by tissue levels of glucose, a putative cryoprotectant that is distributed to tissues during freezing. Frogs receiving exogenous glucose injections prior t...