Standard Operating Procedure: Biochemistry Laboratory Operations

This Standard Operating Procedure (SOP) outlines the mandatory safety, organizational, and technical protocols required to maintain a high-functioning biochemistry laboratory. These guidelines are designed to ensure the integrity of biochemical experiments, protect personnel from hazardous reagents, and ensure the reproducibility of sensitive analytical data. Adherence to these protocols is required for all laboratory staff, researchers, and visitors to maintain compliance with institutional biosafety standards.

Section 1: Pre-Laboratory Preparation and Safety

• Personal Protective Equipment (PPE): Don a clean lab coat, nitrile gloves, and splash-proof safety goggles before entering the workspace.
• Area Inspection: Ensure all work surfaces have been wiped down with 70% ethanol or an appropriate disinfectant prior to starting.
• Documentation: Verify that the lab notebook is prepared with the day’s objectives, reagent concentrations, and planned experimental workflow.
• Equipment Check: Ensure that centrifuges, thermocyclers, and spectrophotometers are calibrated and free of obstructions.
• Waste Management: Confirm that biohazard bags, sharps containers, and chemical waste carboys are available and within capacity limits.

Section 2: Reagent Preparation and Handling

• Labeling: All solutions, buffers, and reagents must be labeled with the chemical name, concentration, date of preparation, and the initials of the preparer.
• Volumetric Accuracy: Always use calibrated micropipettes. Verify volume settings before aspiration and ensure liquid tips are firmly attached.
• Storage Compliance: Return all enzymes and thermolabile reagents to -20°C or -80°C freezers immediately after use to prevent degradation.
• pH Verification: Ensure all buffer pH levels are measured using a calibrated pH meter at the specified temperature; record final readings in the reagent log.

Section 3: Experimental Execution and Technique

• Sterile Technique: Perform all cell culture or microbial work within a certified Class II Biosafety Cabinet (BSC). Flame-sterilize loops and wipe down surfaces with 70% ethanol.
• Centrifugation: Always balance centrifuge rotors by mass (not just volume). Ensure lids are secured before starting the cycle.
• Sample Integrity: Keep protein samples on ice at all times during processing unless experimental conditions explicitly dictate otherwise.
• Cross-Contamination Prevention: Change pipette tips between every sample transfer. Use aerosol-resistant tips for molecular biology applications.

Section 4: Post-Laboratory Cleanup and Shutdown

• Surface Decontamination: Thoroughly clean benches, balances, and shared equipment with the designated disinfectant.
• Waste Disposal: Segregate chemical waste from biohazardous waste; dispose of sharps in puncture-resistant containers.
• Equipment Power-Down: Ensure all electrical equipment (heating blocks, microscopes) is turned off and covered if required.
• Log Entry: Record any anomalies, equipment malfunctions, or reagent depletion in the lab maintenance log.

Pro Tips & Pitfalls

• Pro Tip: Use "reverse pipetting" for viscous liquids (like glycerol or high-concentration stock buffers) to improve volume accuracy and minimize bubble formation.
• Pro Tip: Maintain a digital inventory of reagents using a barcode system to track expiration dates and prevent "bottlenecking" of essential supplies.
• Pitfall (The "Forgotten" Step): Leaving buffers on the bench at room temperature for extended periods is the most common cause of enzyme degradation. Build a habit of "returning to the freezer" as an atomic action.
• Pitfall: Overloading centrifuge rotors or failing to balance them properly is a common cause of mechanical failure and serious safety incidents. Never ignore the centrifuge balance check.

Frequently Asked Questions

Q: What should I do if I spill a hazardous chemical? A: Immediately alert nearby personnel. Refer to the Safety Data Sheet (SDS) for the specific chemical to determine neutralization protocols. If the spill is large or poses a respiratory risk, evacuate the lab and call the campus environmental health and safety (EHS) department.

Q: How often should micropipettes be calibrated? A: Micropipettes should be professionally calibrated and serviced at least once per year. However, if you observe consistent errors in volume transfer, they should be taken out of service for inspection immediately.

Q: Can I store personal food or drink in the lab refrigerator? A: Absolutely not. Laboratory refrigerators are reserved strictly for reagents and biological samples. Storing food in the lab poses a severe cross-contamination risk and is a violation of international biosafety regulations.