Q.28 A roller bottle culture vessel perfectly cylindrical in shape having inner radius (r) = 10 cm and length (l) = 20 cm was fitted with a spiral film of length (L) = 30 cm and width (W) = 20 cm. If the film can support 104 anchorage dependent cells per cm2, the increase in the surface area after fitting the spiral film and the additional number of cells that can be grown respectively are
- (A) 1200 cm2 and 12 × 107 cells
- (B) 600 cm2 and 6 × 107 cells
- (C) 600 cm2 and 8300 cells
- (D) 1200 cm2 and 8300 cells
Increase in Surface Area and Cell Yield in a Roller Bottle Culture Vessel Using Spiral Film
Roller bottle culture vessels are commonly used for growing anchorage-dependent cells.
To increase cell yield, a spiral film can be fitted inside the vessel to enhance the
available surface area. Below is the detailed solution with explanation of all options.
Given Data
- Inner radius (r) = 10 cm
- Length of vessel (l) = 20 cm
- Length of spiral film (L) = 30 cm
- Width of spiral film (W) = 20 cm
- Cell density supported = 105 cells/cm2
Step 1: Increase in Surface Area
Since both sides of the spiral film are available for cell growth:
Surface Area = 2 × L × W
= 2 × 30 × 20
= 1200 cm2
Step 2: Additional Number of Cells
Additional cells grown = Surface area × Cell density
= 1200 × 105
= 1.2 × 108 cells
= 12 × 107 cells
Correct Answer
Option (A): 1200 cm2 and 12 × 107 cells
Explanation of All Options
Option (A): 1200 cm2 and 12 × 107 cells
✔ Correct. Both sides of the spiral film are considered and the cell calculation is accurate.
Option (B): 600 cm2 and 6 × 107 cells
✖ Incorrect. Only one side of the spiral film is considered.
Option (C): 600 cm2 and 8300 cells
✖ Incorrect. Both surface area and cell number are wrongly calculated.
Option (D): 1200 cm2 and 8300 cells
✖ Incorrect. Surface area is correct but cell number is severely underestimated.
Conclusion
The spiral film increases the available surface area by
1200 cm2, allowing the growth of
12 × 107 additional anchorage-dependent cells.
Hence, Option (A) is the correct answer.
