GATE 2019 BT – Question 55

Recombinant DNA Technology and Other Tools in Biotechnology · Analytical tools: Microscopy and spectroscopy · 2 marks · Numerical answer

A UV-visible spectrophotometer detects absorbance down to 0.02. Protein molar extinction coefficient is 10000 L/(mol cm), and cuvette path is 1 cm. Find minimum reliably measurable concentration in μM.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 2 to 2

Explanation

Beer–Lambert law gives $c=A/(\epsilon l)=0.02/(10000\times1)=2\times10^{-6}$ mol/L. Converting to micromolar gives 2 μM. This is the concentration corresponding to the instrument’s stated absorbance threshold.

More Analytical tools: Microscopy and spectroscopy questions

GATE 2024 BT Q11 – In adsorption chromatography, the adsorption of uncharged solute molecules onto a…
GATE 2024 BT Q41 – Match the item in Column I with the corresponding technique in Column II. Column I Column…
GATE 2025 BT Q60 – The percentage of light that would pass through a sample with an absorbance of 2 would be…
GATE 2025 BT Q64 – An NMR spectrometer operating at proton resonance frequency () of 1 GHz will have a…
GATE 2023 BT Q28 – Which one of the following methods CANNOT be used to determine the secondary structure…
GATE 2023 BT Q57 – A protein has three identical sites at the vertices of an equilateral triangle. One donor…

All Analytical tools: Microscopy and spectroscopy questions →