Libraries at University of Nebraska-Lincoln


Document Type


Date of this Version



Thesis (M.S.)—University of Nebraska—Lincoln, 1955. Department of Physiology.


Copyright 1955, the author. Used by permission.


The present work was undertaken with the following objectives in mind:

(1) to determine the effect of various concentrations of trypsin upon a pure strain of cells in vitro,

(2) once this effect has been established, determine the optimum and nontoxic concentrations of trypsin, and

(3) determine the effect of various concentrations of trypsin upon the morphology of the cells.

In this study, various explanations for the mechanism of trypsin action in the stimulation of cell growth are discussed. Replicated cultures of Earle’s Strain L Cells were prepared in order to determine the effect of trypsin on the proliferation of these cells.

The cultures were treated with nutrient media containing the following concentrations of trypsin: (1) 250 mg, (2) 125 mg, (3) 62.5 mg, (4) 36.25 mg, and (5) 15.625 mg percent. The 250 mg and 125 mg percent concentrations were found to be toxic to the cells. Exposure to the cells to 62.5, 36.25 and 15.625 mg percent trypsin resulted in considerable acceleration in rate of growth.

Morphologically, trypsin seemed to have no direct effect on the cell.Any morphological changes observed seemed to be secondary either to the rapid multiplication of the cells or the decrease in cell number.

Trypsin can be used to free Strain L Cells from their substratum without any detrimental effects, providing the cells are immediately and adequately washed.

Advisor:D. M. Pace