Method for manufacturing product

A method for manufacturing a product obtained by culturing cells, the method comprising:

• a culture step of culturing the cells in a culture solution accommodated in a tank;
• and
• a separation step of using a hollow fiber membrane filter which has a hollow fiber membrane having a primary flow passage extending in a longitudinal direction inside the hollow fiber membrane and has a housing accommodating a plurality of the hollow fiber membranes, the hollow fiber membrane filter having a secondary flow passage in a space of the housing outside each of the hollow fiber membranes, to feed the culture solution supplied from the tank to the primary flow passage, and allowing a permeated liquid containing the product to permeate through the secondary flow passage to separate the cells and the product in the culture solution from each other,
• wherein, in the separation step, in a case where a difference in pressure between both ends of the primary flow passage on a supply side and a discharge side during the feeding of the culture solution is denoted as ΔP [Pa], a membrane resistance of the hollow fiber membrane is denoted as r [Pa/mL/min] represented by Expression 1, and a flow passage resistance of the secondary flow passage is denoted as R [Pa/mL/min] represented by Expression 2, ΔP/2(r+R) during the feeding of the culture solution is 0.0005 mL/min or less,
• r
• =
• μ
• ⁢
• k
• ·
• ln
• ⁡
• (
• D
• /
• d
• )
• /
• 2
• ⁢
• π
• ⁢
• L
• ×
• 1000
• /
• 60
• ,
• Expression
• ⁢
• 1
• R
• =
• 8
• ⁢
• μ
• ⁢
• LM
• /
• π
• ⁢
• A
• ⁡
• (
• reff
• )
• 2
• ×
• 1
• ⁢
• 000
• /
• 60
• ,
• Expression
• ⁢
• 2
• here, μ [Pa·s] is a viscosity of the culture solution, k [1/mm2] is a pressure loss coefficient of the hollow fiber membrane, D [mm] is an outer diameter of the hollow fiber membrane, d [mm] is an inner diameter of the hollow fiber membrane, L [mm] is a length of the hollow fiber membrane, M is the number of the hollow fiber membranes accommodated in the housing, reff [mm] is a hydraulic radius of the hollow fiber membrane filter represented by Expression 3, A [mm2] is a cross-sectional area of the secondary flow passage in a cross section perpendicular to the length direction of the hollow fiber membrane filter, and Dh [mm] in a following Expression 3 is an inner diameter of the housing,
• reff
• =
• π
• ⁡
• (
• D
• h
• 2
• -
• M
• ·
• D
• 2
• )
• /
• 2
• ⁢
• π
• ⁡
• (
• D
• h
• +
• M
• ·
• D
• )
• .
• Expression
• ⁢
• 3