Trypsin treatment

For cell cycle analysis, HOS cells (1 x 106) were treated with the indicated concentrations (see Table 13.2) of MTX or MTX-LDH for 20h, harvested by trypsin treatment, washed with PBS, and then fixed with cold 70 % ethanol on ice overnight. The fixed cells were incubated with propidium iodide and flow cytometric measurement was carried out. Over 20 h, an increase in the number of cells in the Gl phase resulted from MTX and MTX-LDH treatment compared to untreated cells, indicating arrest at the Gl/S boundary. It is worth noting that the inhibition of the Gl/S transition was more evident in the cells treated with MTX-LDH than in those treated with free MTX (85.59% versus 66.62% at 320pM/ml). This is consistent with... 

Trypsin treatment is described to remove cell-associated lipids after treatment with 0.25% trypsin for a few minutes (better effects are seen with increased incubation time and phosphatidylcholine concentration) (149). 

The hepatocytes was subcultured for 2 days and their albumin secretion activity was measured. The TRS-harvested hepatocytes showed nearly the same albumin secretion activity as the primary culture, whereas the ERS-harvested ones showed only 20% activity. This finding is important because no subculture of hepatocyte has ever been successful, owing to a possible proteolytic disruption of cell-membrane structure (especially cell-cell adhesion) in the course of trypsin treatment. 

Gregory, J. F. and Shipe, W. F. 1975. Oxidative stability of milk. I. The antioxidative effect of trypsin treatment and aging. J. Dairy Sci. 58, 1263-1271. 

The trypsin treatment tells us that Arg is the second amino acid from the N-terminus. Therefore, angiotensin II is ... 

Biomimetic sensors, prepared by catalase adsorption on diasorb and agarose (treated with trypsine) and adhered to an aluminum electrode surface by Pattex adhesive, displayed an abrupt decrease of the electrode potential. Sensors prepared by catalase adsorption on A1203 (without trypsine treatment) and adhesion to the aluminum electrode with Pattex adhesive displayed a high oscillation of the electrode potential, which induces extreme instability of the operation. Hence, it should be noted that sensor operation was always better in the case of enzyme treatment with trypsine. 

For cells growing continuously in suspension, the subculture process can be performed similarly to the method used for microbial cultures. Trypsin treatment is not required and subculture is faster and less traumatic for the cells. Total medium exchange is not generally performed for these cultures since it would require a centrifugation step. Culture maintenance can be performed by dilution with fresh medium after adequate cell growth. 

How proteinase works to achieve this improvement has not yet been elucidated. Lynn (2003 a) demonstrated that, in spite of the fact that trypsin treatment can increase infectivity of baculovirus, this enhancement does not happen for all cell-virus systems. AcMNPV infectivity of Trichoplmia ni (TN-368) cells increased 4750-fold using trypsin. For Anagrapha falcifera NPV (AfMNPV), the improvement was 77 000- fold. On the other hand, the infectivity of these two viruses for the Lymantria dispar (LIPLB-LdE) cell line was slightly reduced. 

EC monolayers obtained after growth on either collagen-coated glass coverslips, or tissue culture multiwell plates as previously described (Sections 2.3.3.1 and 2.3.3.2), are rinsed several times in serum Iree medium, and then incubated 1 h at 37°C with assay medium (usually serum free culture medium supplemented with 0.5-1% BSA), before they are used as substrates for the adhesion assay. Tumor cells are detached from culture dishes either by EDTA or by trypsin treatment. In the latter case, trypsinized cells should be allowed to recover from the enzyme treatment in their growth medium for 30 min at 37°C. After rinsing in serum-free medium, labeled tumor cells are resuspended at the desired concentration in the assay medium and plated onto the EC monolayer at a cell concentration ranging between 10 and 2 x 10 /cm. Incubation is... 

The NA spikes can be eluted by pronase or trypsin treatment, yielding crystallisable, enzymatically-active, and antigenically equivalent tetramers, which has allowed thdr three-dimensional structure to be determined. 

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