Preservation of cells and tissues by freezing at temperatures below 70°C has led to new possibilities for the storage of germ cells for fertility preservation. During the freezing process problems might occur, the greatest being Ice crystallization which can cause membrane destruction and thus cell death. To minimize this risk, solutions that reduce the freezing point can be added to reduce crystallization and increase survival rates. These solutions are called cryoprotectants. The best method for freezing is still not known.The aim of this study was to analyze the effect of various parameters on the survival rate of human semen frozen with liquid nitrogen.

The production of cheese is in continuous development with objectives to in-crease productivity, achieve changes in shelf life and functional properties of the products. One concept in the development is to substitute milk fat with vegetable fats and oils in the manufacture of cheese. The objective of this study was to investigate effects on cheese yield and cheese quality of 4 different semi-hard analogue cheese products produced by substituting milk fat with vegetable fat, each analogue cheese with a specific mixture of vegeta-ble fat. As reference a cheese produced with anhydrous milk fat was used. The yield and recovery of fat and protein were determined by recording the weights of each cheese direct after press and after 20±2 days of storage and analysis of the composition of the cheeses after 20±2 days of storage. The cheese was fur-ther subjected for texture profile analysis in a TA-XT Plus Texture Analyser and analysed with Differential Scanning Calorimetry (DSC) to examine whether the fat behaves similar in the cheese as in pure form in respect to its thermal properties. The cheese yield was not significantly different when using different fats. Differ-ent amounts of water were absorbed during the water cooling.

LevMacinstrumentet är ett analysinstrument under utveckling som utnyttjar leviterade droppar på 100 nl ? 2 ?l. Genom att använda leviterade droppar med den omgivande atmosfären som enda kontaktyta, undviker LevMac?en de vanligaste problemen associerade med miniatyrisering av analytiska tekniker, t.ex. kontaminering av provet genom desorption från provbehållaren eller andra gränsytor, adsorption av analyten till omgivningen med minskat utbyte som följd, och optisk interferens vid väggarna av provbehållaren vilket resulterar i störningar av detektionen.Tillsatser till den leviterade droppen kan göras i pl-området och reaktioner i droppen kan följas med olika spektroskopiska tekniker.