Cell transfer experiments

Cell transfer experiments indicate that lymphoid cells from the two lines have diverse potentialities. 

Figure 5.9 Cell-transfer experiment transfer of spleen cells from normal High or Low responders into outbred immuno-suppressed recipients. 3 x 10 SE are injected intravenously together with spleen cells. A X rays 950 rad 24 hours before transfer B Cyclophosphamide treatment 6 mg per mouse intraperitoneally 6 hours before transfer.

Figure 1. Long term growth of TFl induced by epithelial MMCE cells expressing membrane-boimd SCF. Long term growth of TFl cells was determined by serial clone transfer experiments. 48 clones from several independent experiments with cell numbers >510 cells were transferred on new feeders dining the first and second transfer. Each point represents the mean ( SD) of five independent experiments. The results are calculated as % of TFl/SL MSS control cocultures. C.E.s at the first clonal transfer of TFl cells were set to 100%. t MMCE transduced with cDNA for mb SCF, s MMCE transduced with cDNA for soluble SL SCF, C parental MMCE, I SLMS5.

In order to investigate the kinetics of a reaction with the stirred cell, firstly experiments are carried out using a suitably related system in which gas absorption takes place by a purely physical mass transfer process (i.e. no reaction occurs). This establishes values of the physical mass transfer coeffient kL for the range of stirrer speeds employed. Then the rate of gas absorption into the liquid with the reaction occurring is measured. Finding the rate constant for a fast first-order reaction, for example, is then a matter of working back through equation 4.13 to find the value of P and hence of kt. 

Cell lysis under a high electric field is referred to as electroporation [6], Under these conditions, the cell membrane experiences dramatic changes in permeability to macromolecules. The main applications of the electroporation include the electrotransformation of cells and the electroporative gene transfer by the uptake of foreign DNA or RNA (in plants, animals, bacteria, and yeast). The electric field generates permeable microspores at the cell membrane, so that the nucleic acid can be introduced by electroosmosis or diffusion. 

Contaminating microorganisms may be present in the cells when these are obtained. The procedures for obtaining primary cells should ensure the exclusion of contamination, but all cells entering the laboratory should be tested before carrying out transfer experiments in rooms being used for other cell transfers. 

Green fluorescent protein is commonly used for energy-transfer experiments (Baubet etal. 2000). The fluorescent moiety of GFP protein is the Ser-Tyr-Gly derived chromophore. GFP can be expressed in a variety of cells where it becomes fluorescent, can be fused to a host... 

Comparison of four CPPs— penetratin (5), Tat (6), transportan (12), and model amphipathic peptide (MAP) (13)— revealed that a model peptide cargo was most efficiently delivered into Bowes melanoma cells by MAP and transportan peptides. As judged by energy transfer experiments (31), the intracellular concentration of a cargo peptide delivered into cells by penetratin or Tat remained three- to fourfold lower compared with transportan- and MAP-mediated delivery. On the other hand, transportan and MAP were more noxious to cells and increased the plasma membrane permeability at lower concentrations. Import of penetratin sequences by the melanoma-derived SKMel-37 cells was in turn three- to fourfold more efficient than uptake of MTS-sequences as measured by fluorescence correlation spectroscopy in living cells and by FACS analysis (32). 

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