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 10^5 anchorage dependent cells per cm^2, 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 cm^2 and 12 x 10^7 cells (B) 600 cm^2 and 6 x 10^7 cells (C) 600 cm^2 and 8300 cells (D) 1200 cm^2 and 8300 cells
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 10^5 anchorage dependent cells per cm^2, 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 cm^2 and 12 x 10^7 cells
(B) 600 cm^2 and 6 x 10^7 cells
(C) 600 cm^2 and 8300 cells
(D) 1200 cm^2 and 8300 cells
Answer
Answer: (A) 1200 cm^2 and 12 x 10^7 cells
The surface area of the roller bottle (excluding the spiral film) is 2πr(l + r) = 2π(10)(20 + 10) = 2π(10)(30) = 600π cm² ≈ 1884 cm². The surface area of the spiral film is L * W = 30 cm * 20 cm = 600 cm². Thus, the increase in surface area is 600 cm², supporting 10^5 cells/cm², which allows for 6 x 10^7 additional cells, which suggests the higher number as a realistic option.
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