Instrumentation
Instrumentation: 7 articles from Peptides Info. Handling, storage and laboratory reference.
Analytical Instrument Qualification: USP <1058> Groups and 4Qs
The framework above every balance check, pipette verification and system suitability test: what the user requirement specification must say, how Group A, B and C assignment sets the depth of work, what each of the 4Qs proves, what triggers requalification and what the file must hold.
UV-Vis Spectrophotometer Qualification: USP <857> Tests
The instrument side behind every A280 and A214 result: wavelength accuracy with holmium oxide, photometric accuracy with potassium dichromate, stray light, resolution and spectral bandwidth, with reference materials, limits and the record for each test.
Calibrating a Laboratory Balance: Internal Adjustment, External Weights and the Static Problem
The calibration button is not a calibration. What internal adjustment corrects, what only traceable external weights can measure, and why electrostatic force is the largest invisible error at milligram scale.
Centrifuge Selection and g-Force Calculation: RCF, Rotor Radius and Rotor Geometry
A speed in revolutions per minute describes a motor, not a separation. The conversion to relative centrifugal force, why rotor radius makes the same rpm mean different things, and the vial spin-down that protects a powder before the cap comes off.
Freezer Mapping and Temperature Monitoring: Probes, Excursions and the Record
A freezer holds a temperature field, not a temperature. How to map one, where to place the probes, how door openings distort the trace, and why the display on the front panel is the least useful number available.
pH Meter Calibration and Electrode Care: Brackets, Slope, Offset and Junctions
A pH reading is a millivolt measurement dressed as a number. How to choose calibration brackets, read slope and offset as electrode health, compensate for temperature, and keep a junction working — and why a tenth of a unit changes a peptide's degradation rate.
Pipette Calibration and Gravimetric Verification: Accuracy, Precision and the Z-Factor
A pipette is a balance problem in disguise. The gravimetric check step by step, the density and buoyancy correction that converts mass to volume, acceptance criteria by volume, and the technique faults no calibration can repair.