The Spectrophotometer

Dr. Smith stands by the spectrophotometer in the lab, gesturing for her students to gather around. ‘Alright, everyone, we've discussed how our centrifuge can separate cells or fractions. Now let's shift gears and talk about the spectrophotometer. This instrument measures how much light passes through or is absorbed by a sample at a specific wavelength. It's crucial for things like determining bacterial growth in a liquid culture or analyzing protein concentrations.’

Emma peers into the chamber and remarks excitedly, ‘I can just pour my sample directly into here, right, Dr. Smith? That’ll make things faster.’

Smiling gently but shaking her head, Dr. Smith responds, ‘Not exactly, Emma. If we simply pour the sample in, we'd risk damaging the machine and getting irreproducible results. We always use cuvettes—clean, fingerprint-free cuvettes—to hold our samples.’ 

Spectrophotometer (Viv Rolfe, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons) 

Dr Smith: ‘Let’s consider some situations where we need to use a spectrophotometer. ‘

You: ‘When we discussed the centrifuge, we said that we may use it during the monitoring of algae growth in water samples.’ 

Dr Smith nods in agreement. She also decides to test student knowledge by proposing two more experiments.