nna is training to be a cell culture technician. She uses some sterile distilled water to wasg a batch of cell culture plates. When she looks at the cell culture plates under the microscope to check the cells after this, she notices the cell have burst. She realizes she should have used 0.9% saline instead. Explain what has happened, and why she should have used the saline.

Three actively growing cultures of the same strain of yeast (saccharomyces cerevisiae) are used. Culture A has been incubated for 48 hours and Culture B has been incubated for 24hours and Culture C for 6 hours. a) Make a drawing of the cells from each culture to identify the various stages of the cell division. b) Is there any difference between the 3 cultures?

In a plate count, 1 mL of culture is spread on a plate and incubated for 24 hours. 250 colonies are counted. Answer the question below. there were _____cells in the 1 mL of culture that was spread on the plate. If the culture was diluted 1:100 prior to plating, how many cells were there per mL in the original culture? _________

There are two cultures of yeast cells in the pictures, one has been incubated for 6 hours and one has been incubated for 24 hours. After a 10x dilution by taking 100µl of each culture and adding it to 900 µl water in a microcentrifuge tube and 100µl sample from the tube was taken to view in the counting chamber. a) Count the total number of yeast cells for each culture respectively b) Calculate the concentration and density of yeast cells for each culture respectively

You are doing a viable cell count for a culture of E. coli you are growing in a flask. The volume of media in the flask is 1L. You took an aliquot directly from the media and diluted it using trypan blue. Here are the numbers that you get:   squares counted: 4 total cells counted: 988 total viable cells counted: 960 THESE ARE THE QUESTIONS: What is your cell viability? What is the total number of viable cells in your flask? Show all work.  Given:  Cell Viability = Viable Cells/Total Cells Cells/mL = Total Viable Cells/Coners Counted x 10,000 x Dilution factor

Please written by computer source 1. We want two T-75 flasks, each with 200,000 cells in the flask that holds 20 mL of culture medium per flask. Hemocytometer counting of cells in a 1 mm sq2 area gave an average of 12 cells from a 1:9 dilution of the cell suspension.   a.) Determine the cells/mL. b.) What is the volume of your cell suspension needed to make the flasks? c.) How you would now make the flasks as a new subculture of cells for incubation?

A lab technologist calibrates her microscope and finds that 7 stage divisions are equal to 38 ocular divisions. The entire scale on the stage micrometer is 1 mm long and has 100 equal divisions.  The technologist measures a coccus-shaped cell and determines that the cell is 4 ocular divisions in length.  What is the length of this cell in µm?  Show all calculations.

If the 1-mL sample had been added to 99 mL of diluent to make the first dilution (instead of 9 mL), how many cells would be in that particular dilution?

Why must primary cell cultures be restarted every so often when preparing primary cell cultures to observe morphological changes caused by cells infected by a virus? Why are tumor cells preferred?

Jon performed a pour plate technique to determine the concentration of viable cells in her mother culture for nata de coco production. Prior to all the samples, he poured an extra Petri dish without any sample with the molten agar. What is the purpose of doing this?