Which of the following is an advantage of the standard plate count?
Which of the following is an advantage of the standard plate count?
The correct answer: An advantage of the standard plate count is that it e. Determines the number of viable cells.
Which of the following is an advantage of the standard plate count group of answer choices?
Microbiology
| Question | Answer |
|---|---|
| Which of the following is an advantage of the standard plate count? | determines the number of viable cells |
| Most bacteria reproduce by | binary fission |
| During which growth phase will gram-positive bacteria be most susceptible to penicillin? | log phase |
Which of the following would be a method used to count cells that are alive?
Cells can be counted by direct viable cell count. The pour plate and spread plate methods are used to plate serial dilutions into or onto, respectively, agar to allow counting of viable cells that give rise to colony-forming units. Membrane filtration is used to count live cells in dilute solutions.
How do you calculate cells?
To calculate the cell concentration, take the average number of viable cells in the four sets of 16 squares and multiply by 10,000 to get the number of cells per milliliter. Then, multiply this by five to correct for the one in five dilution from the trypan blue addition.
How do you count cells?
To count cells using a hemocytometer, add 15-20μl of cell suspension between the hemocytometer and cover glass using a P-20 Pipetman. The goal is to have roughly 100-200 cells/square. Count the number of cells in all four outer squares divide by four (the mean number of cells/square).
How do you count PBMC cells?
The viability and concentration of isolated PBMCs are traditionally measured by manual counting with trypan blue (TB) using a hemacytometer. One of the common issues of PBMC isolation is red blood cell (RBC) contamination
How do I count the number of cells with text?
To count the number of cells that contain text (i.e. not numbers, not errors, not blank), use the COUNTIF function and a wildcard. In the generic form of the formula (above), rng is a range of cells, and “*” is a wildcard matching any number of characters.
How do you calculate viable count?
The total number of colonies is referred to as the Total Viable Count (TVC). The unit of measurement is cfu/ml (or colony forming units per milliliter) and relates to the original sample. Calculation of this is a multiple of the counted number of colonies multiplied by the dilution used.
What is the difference between total count and viable count?
The main difference between the two is that total count determines the count of all cells both dead and alive while viable count estimate the number of viable or live cells only capable of growing into distinct colonies
What is total viable aerobic count?
Total viable count (TVC) is a test that estimates the total numbers of microorganisms, such as bacteria, yeast or mould species, that are present in a water sample. TVC may also be expressed as aerobic colony count
What is the formula for calculating CFU?
To find out the number of CFU/ ml in the original sample, the number of colony forming units on the countable plate is multiplied by 1/FDF. This takes into account all of the dilution of the original sample. For the example above, the countable plate had 200 colonies, so there were 200 CFU, and the FDF was 1/4000.
Which method is used to determine the number of bacteria quantitatively?
The two most widely used methods for determining bacterial numbers are the standard, or viable, plate count method and spectrophotometric (turbidimetric) analysis
What is total bacterial count?
Total bacterial count (TBC) is the count of the number of bacterial colony-forming units present in the milk sample, giving a quantitative evaluation of the total number of bacterial colony-forming units per milk milliliter (Ministério da Agricultura, Pecuária e Abastecimento, 2003.
What is a high bacteria count?
What Is It? Bacterial colonization in urine is high when the level of bacterial counts is elevated— meaning the number of colonies of a single organism is higher than 100,000 per mL. If the bacteria level in your urine is high and it’s causing physical symptoms, you have a symptomatic urinary tract infection (UTI).
What is the most widely used method of counting bacteria?
Viable Count The most common procedure for the enumeration of bacteria is the viable plate count. In this method, serial dilutions of a sample containing viable microorganisms are plated onto a suitable growth medium.
How do you identify bacteria on agar?
Colony morphology is a method that scientists use to describe the characteristics of an individual colony of bacteria growing on agar in a Petri dish. It can be used to help to identify them. A swab from a bin spread directly onto nutrient agar. Colonies differ in their shape, size, colour and texture.
How do you count bacteria on agar plates?
Use the formula: [Number of colonies counted] × 10 × [how many times the sample must be multiplied to get to the original concentration: for example, 105] = Number of colony forming units (CFU) per milliliter of starting culture. This is the bacterial growth in your petri dishes
What is considered the most accurate countable range for colonies on a plate?
30-300
What unit is used to measure bacteria?
micrometer
What are the 4 phases of bacterial growth?
Most bacterial cells divide by binary fission. Generation time in bacterial growth is defined as the doubling time of the population. Cells in a closed system follow a pattern of growth with four phases: lag, logarithmic (exponential), stationary, and death.
What is the biggest microorganism?
Thiomargarita namibiensis
Which cell is the longest?
Nerve cells