Suspensions of Lactobacillus leichmannii were stored in liquid nitrogen and were used as direct inocula in vitamin B(12) assays. Complete recovery of viable cells was obtained when the suspensions in basal B(12) medium were rapidly frozen by direct immersion into liquid nitrogen and rapidly thawed by agitating the suspensions in a water bath at 40 C. Greater than 90% destruction occurred when t...

Semen samples were collected from eight males of Goldfish (Carassius auratus gibelio) and cryopreserved using four extenders (Goldfish sperm extenders; GFSE 1– GFSE 4) supplemented with Methanol (MeOH) at concentration of 5%, 10% and 20%. Semen was diluted with ratio of 1:1 with extenders and frozen in liquid nitrogen vapor. Frozen sperms after 2 and 5 days were excluded from freezing. Experime...

The aim of this study was investigation of various levels of vitamin E in Tris extender on semen characteristics of Ghezel rams in pre and post freezing conditions. Semen was collected from six healthy and mature rams with average 55±5 Kg body weight by electro ejaculator. High quality samples were mixed and diluted in Tris extender after apply different concentration of vitamin E. Treatments w...

BACKGROUND The demonstration of tissue-bound immunoreactants by direct immunofluorescence microscopy (DIF) is a valuable parameter in the diagnosis of various autoimmune and immunecomplex-mediated skin diseases. For preservation of tissue-bound immunoreactants, biopsies are usually fresh-frozen in liquid nitrogen or transported in Michel's fixative. But even optimally preserved tissue specimens...

this study was carried out to determine the potential of rumen microorganisms in samples taken from slaughterhouse to produce fibrolytic enzymes and to compare different methods for extraction, concentration and conservation of them.  according to the results, the average specific activity of cellulase and xylanase were 7.5 and 16.5 u/mg protein respectively. the application of homogenizing and...

Isolated tomato (Lycopersicon esculentum var. Kc 146) fruit mitochondria could be stored successfully in the frozen state without a cryoprotective agent if the mitochondria were frozen quickly by immersion in liquid nitrogen and later thawed quickly at 30 C. Criteria of freezing damage were rate of respiration, adenosine diphosphate to oxygen ratio, and respiratory control ratio. Marked reducti...

Abstract In this study, microfunnel-supported liquid-phase microextraction method (MF-LPME) was optimized and applied for the determination of some chlorophenoxyacetic acids (CPAAs) from natural water samples. The extraction was performed with 540 μL toluene which was retained at the surface of the sample solution using an upside down microfunnel. After the extraction, toluene was moved in...