Question

Which of the following technique separates the sample by percolating it through a bed of porous, uncharged particles?

(a) Gel filtration

(b) Filtration

(c) Dialysis

(d) Ultrafiltration

The question was posed to me in an interview for internship.

Enquiry is from Enzymes Purification in division Enzymes Purification of Enzyme Technology

Answer 1

The correct answer is (a) Gel filtration

For explanation I would say: Gel filtration separates the sample by percolating it through a bed of porous, uncharged particles. Filtration simply separates based on the size across a permeable membrane. Ultrafiltration is a type crossflow microfiltration technique where in the sample flow is tangential to the membrane to avoid the building of the cake. Dialysis is a process which allows the passage of low molecular weight compounds retaining the high molecular weight compounds inside the membrane.