Have a go at this diagnostic test before diving into the rest of the book. Complete the questions without a calculator and give yourself about 30 minutes in total. Check your answers afterwards and reflect on what you might need to focus on. Don’t worry if you are new to a concept! The underlying concepts and skills required to solve these problems are covered in later sections of this book.

Each answer is worth 1 mark, for a total of 20 marks.

Side Bar – Bovine serum albumin (BSA) as the name implies is protein found in cow’s blood. As it is abundant, easy and cheap to purify, small and stable it has found many uses in biochemical and clinical diagnostic laboratories. One such use is as a protein standard for determining unknown protein concentrations in biological extracts.

Side Bar – Square brackets, [ ], are often used as an abbreviation for the term concentration. e.g. a 0.1 molar hydrogen ion concentration can be referred to by [H^{+}] = 0.1 M.

Side Bar – Often concentrations are expressed as an amount per volume such as moles per litre or grams per millilitre. There are several valid ways to express concentrations, or in fact any rates or ratios which involve dividing one unit by another (e.g. kilometres per hour). It is worth becoming familiar with them. *Per* as in grams per millilitre is sometimes denoted with as a slash to indicate division (g/ml) or to indicate that ml is the denominator it can be expressed using a negative exponent (g.ml^{-1}).