BRL117 Lab 1: General Lab Skills

Comprehensive vocabulary flashcards covering safety rules, measurement tools, micropipetting, metric conversions, buffers, serial dilutions, and spectrophotometry from BRL117 Lab 1.

Rutgers Environmental Health and Safety (REHS)

The university safety division that developed the laboratory safety, chemical handling, and dress code regulations for the Biological Research Laboratory.

Laboratory Dress Code

Safety dress policy prohibiting bare midriffs, sleeveless or cap-sleeve tops, shorts, skirts/dresses without proper pants, open-toed shoes, and netting/mesh, while mandating close-toed shoes, high crew/tube socks, and pants fully covering legs and ankles.

Chemical Splash Protocol

Emergency procedure requiring that if a chemical splashes on skin or in eyes, the affected area must immediately be flushed at an eyewash or safety shower for at least $30\,\text{minutes}$ while contaminated clothing is removed.

Splash-Proof Safety Goggles

Protective eyewear required during laboratory experiments whenever potentially hazardous solutions with a $\text{pH} < 5$ or $\text{pH} > 8$ are transferred.

Ethidium Bromide (EtBr)

A chemical mutagen capable of intercalating into DNA that must be handled with gloves at all times and disposed of in a specialized Ethidium Bromide waste container.

Autoclave

A specialized laboratory machine that sterilizes bacterial media, plates, cultures, and equipment using high pressure, heat, and/or steam.

Assay

A scientific analytical tool or procedure used to quantitatively measure the amount of a single specific component within a total sample (e.g., the Biuret assay for protein content).

LabQuest 3

A standalone interface device that reads measurements from Vernier probes and sensors, displays real-time graphical data, and stores experimental information electronically.

Accuracy

The closeness of an experimental measurement to its true or accepted value.

Precision

The ability to repeatedly measure a value under identical conditions and obtain consistent, reproducible results.

Accuracy vs. Precision (Target Comparison)

A target analogy in which the proximity of shots to the bullseye represents accuracy, while the closeness of the cluster of shots to one another represents precision.

Significant Figures (SF)

The digits in a measured number that carry meaning and reflect the measurement resolution of the instrument used to obtain the data.

Significant Figure Determination Rules

Three rules stating: 1. Non-zero digits are always significant; 2. Zeros located between two significant digits are significant; 3. Trailing zeros are significant only in the decimal portion of a number.

Even/Odd Rounding Rule for 5

A rounding rule where if the digit preceding an ending 5 is odd, round up; if the digit preceding the 5 is even, leave it unchanged, ensuring rounding errors average out over many calculations.

Meter

The standard metric unit of length, established as one ten-millionth ($10^{-7}$) of the distance from the Earth's pole to the equator along the meridian passing through Paris.

Liter

The standard metric unit of volume, defined as the volume of one cubic decimeter ($10\,\text{cm}$ on all sides).

Gram

The standard metric unit of mass, defined as the mass of $1\,\text{ml}$ of pure water at $4^\circ\text{C}$, where the density of water is defined as $1.00\,\text{g/ml}$.

Density

The mass of a substance divided by its volume ($\text{Density} = \frac{\text{mass (g)}}{\text{volume (ml)}}$), typically expressed in units of $\text{g/ml}$.

Pan Balance Bubble Level Indicator

A circular leveling window with a central ring; the balance feet must be adjusted until the bubble is fully centered to ensure accurate mass determination.

Tare

The process and button on a pan balance used to zero out the readout with a secondary container (such as a weigh boat or microfuge tube) in place before adding sample mass.

Transfer Pipet

A disposable plastic Pasteur pipette with side graduations used to transfer unmeasured or approximate liquid volumes of less than $1\,\text{ml}$.

P-20 Micropipette

A micropipette calibrated in $0.1\,\mu\text{l}$ increments that dispenses liquid volumes from $2\,\mu\text{l}$ to $20\,\mu\text{l}$.

P-200 Micropipette

A micropipette calibrated in $1\,\mu\text{l}$ increments that dispenses liquid volumes from $20\,\mu\text{l}$ to $200\,\mu\text{l}$.

P-1000 Micropipette

A micropipette calibrated in $10\,\mu\text{l}$ increments that dispenses liquid volumes from $100\,\mu\text{l}$ to $1000\,\mu\text{l}$.

First Stop vs. Second Stop

The two mechanical resistance points on a micropipette plunger: pressing to the first stop aspirates the set volume, while pushing to the second stop completely expels residual liquid from the tip.

Serological Pipette

A graduated pipette attached to a reusable bulb used to measure and transfer milliliter-range liquid volumes ($1\text{--}5\,\text{ml}$ or $1\text{--}10\,\text{ml}$).

Sterile Technique (Aseptic Technique)

A set of procedures designed to prevent contamination of reagents, cultures, and biological experiments by keeping pipettes, tips, and vessels free from outside contact.

Buffer

An aqueous solution containing salts, buffering agents, and optional cofactors or detergents that functions primarily to resist changes in hydrogen ion concentration ($\text{pH}$).

Stock Solution

A concentrated starting solution with a known chemical concentration that is diluted with water to make a working concentration (commonly $1\text{X}$).

Dilution Equation ($C_1V_1 = C_2V_2$)

A mathematical formula used to prepare dilutions where $C_1$ is stock concentration, $V_1$ is volume of stock required, $C_2$ is final diluted concentration, and $V_2$ is final total volume.

Dilution Factor (DF)

The ratio by which the concentration of a stock solution is reduced, calculated as $\text{DF} = \frac{C_1}{C_2} = \frac{V_2}{V_1}$.

Serial Dilution

A stepwise series of dilutions in which the dilute solution from the preceding step serves as the stock solution for the subsequent step ($\text{DF}_{\text{total}} = \text{DF}_1 \times \text{DF}_2 \times \dots$).

Vortexer

A motorized benchtop device that rapidly oscillates to agitate and mix small volumes of liquids held in vials, cuvettes, or microfuge tubes.

SpectroVis

A spectrophotometer instrument that passes a selected wavelength of light through a liquid sample into a photometer to measure absorbance and transmittance.

The Blank

A calibration tube containing all solvent and assay reagents without the light-absorbing compound of interest, used to calibrate the spectrophotometer to zero absorbance.

Cuvette

A small, optical-quality square vessel ($3.0\,\text{ml}$) with an alignment arrow that holds liquid samples inside a spectrophotometer light path.

Standard Curve

A graph plotting measured absorbance values against known concentrations of standard serial dilutions, used to determine the concentration of unknown samples.

Proportional Ratio Method ($C_u$)

A formula calculating unknown concentration ($C_u$) directly from a standard of known concentration ($C_s$) and absorbance ($A_s$) and the unknown sample absorbance ($A_u$): $C_u = \frac{A_u \times C_s}{A_s}$.