Lab 1: Micropipette and Dye-Binding Assay Practice Flashcards

This set of vocabulary flashcards covers fundamental micropipette ranges, handling procedures, Beer's Law components, and the specifics of the Dye-Binding (Bradford) protein assay based on Lab 1 objectives.

P2 Micropipette

A micropipette with a designated working range of $0.2 - 2\,\mu L$.

P20 Micropipette

A micropipette with a designated working range of $2 - 20\,\mu L$.

P200 Micropipette

A micropipette with a designated working range of $20 - 200\,\mu L$.

P1000 Micropipette

A micropipette with a designated working range of $100 - 1000\,\mu L$.

Beer's Law

The physical law represented by the equation $A = \varepsilon cl$, where absorbance ($A$) is proportional to concentration ($c$).

Absorbance ($A$)

A unitless value calculated as $-\log(T)$, where $T$ represents transmittance.

Extinction coefficient ($\varepsilon$)

A sample-dependent constant with units of $M^{-1}\,cm^{-1}$ used in Beer's Law calculations.

Path length ($l$)

The distance light travels through a sample, which is $1\,cm$ for the plastic cuvettes used in this lab.

Dye-Binding (Bradford) Assay

A colorimetric protein assay where the protein concentration is proportional to absorbance at $595\,nm$.

BSA (Bovine Serum Albumin)

The protein used in Tubes 1–6 as a standard to create a standard curve for the dye-binding assay.

SDS

A substance that can interfere with the binding of dye to protein in the Bradford assay, tested in Tubes 8 and 9.

Standard Curve

A graph plotting known amounts of protein (Tubes 1–6) against their absorbance to determine the concentration of an unknown sample via the best fit line equation $y = mx + b$.

Interpolation

The process of determining the mass of an unknown protein by reading values within the established range of the standard curve.

Extrapolation

Estimating values beyond the range of the standard curve, a practice that should be avoided according to general lab guidelines.

Micropipette Handling Rules

Operational requirements to never lay a pipette flat or invert it when liquid is in the tip, as it damages the piston and barrel.

Tube No. 1

The specific tube used to blank or zero the spectrophotometer prior to reading experimental samples.