BIOL 225 Lab Final 2026/2027 | 76 Questions & Answers | Spectrophotometry, Micropipetting, Cryopreservation, SDS-PAGE & Cell Biology

This BIOL 225 Lab Final 2026/2027 study guide contains approximately 76 laboratory questions, definitions, calculations, and correct-answer sets designed for comprehensive final-exam preparation in cell biology and biological laboratory methods. The material covers spectrophotometry, standard curves, Beer-Lambert law, micropipetting, serial dilutions, microscopy, laboratory safety, fluorescence staining, hemocytometer cell counting, cryopreservation, centrifugation, mitochondrial enzyme assays, Bradford protein assays, electrophoresis, and SDS-PAGE. It combines theoretical laboratory concepts with calculations, experimental procedures, equipment use, data interpretation, and troubleshooting skills. The quantitative laboratory section reviews spectrophotometers, absorbance, chromogens, standard curves, linear trendlines, and the Beer-Lambert relationship (A = kLC). Students practice calculating unknown concentrations with linear equations and applying C1V1 = C2V2 to solution preparation. The guide also explains 1/100 and serial dilutions, total dilution factors, plating efficiency, and concentration calculations. Detailed micropipette coverage includes P10, P20, P200, and P1000 operating ranges, appropriate tips, correct handling procedures, and precautions designed to prevent contamination and equipment damage. Laboratory microscopy and imaging topics include the compound light microscope, Köhler illumination, DAPI staining, rhodamine-phalloidin staining, fluorescence excitation and emission, F-actin visualization, and DNA/nuclear staining. The material explains how fluorescently labelled human cheek cells can be interpreted, with DAPI identifying A-T-rich DNA regions and rhodamine-phalloidin identifying F-actin within the cytoskeleton. It also reviews methylene-blue absorbance and the use of standard curves to estimate unknown dye concentrations. A substantial section covers cell counting, cell viability, yeast culture, cryopreservation, and cryoprotective agents. Topics include hemocytometers, ten-fold serial dilution, plating efficiency, methylene-blue viability testing, glycerol and DMSO treatments, controlled freezing, centrifugation after thawing, and removal of cryoprotective agents before cells are returned to fresh growth medium. These questions connect experimental design with practical interpretation of viable and nonviable cells. The cellular respiration section concentrates on mitochondrial isolation, differential centrifugation, succinate dehydrogenase (SDH), the electron transport chain, DCIP, sodium azide, succinate, and spectrophotometric enzyme assays. Students review how mechanical disruption and sequential centrifugation separate cellular components, including nuclei, mitochondria, membranes, and ribosomes. The material also examines how SDH activity can be measured indirectly using DCIP as an artificial electron acceptor and how experimental inhibitors affect electron transport. Protein-analysis material covers the Bradford assay, bovine serum albumin (BSA) standards, Coomassie Brilliant Blue, electrophoresis, and SDS-PAGE. Students review protein-concentration calculations and the functions of beta-mercaptoethanol, sodium dodecyl sulfate (SDS), bromophenol blue, and glycerol in sample preparation. The guide further addresses vertical electrophoresis and the principle of separating SDS-treated proteins primarily according to molecular size. Laboratory safety is also extensively represented, including general laboratory conduct, biological and chemical waste, personal protective measures, fire-extinguisher classes, compressed gases, flammable and combustible substances, oxidizing materials, toxic substances, biohazardous infectious materials, corrosives, and dangerously reactive materials. This makes the document particularly useful for a laboratory final that assesses both experimental biology and safe laboratory practice. Relevant students: This document is relevant for BIOL 225 students, cell biology laboratory students, molecular biology students, biochemistry students, biomedical science students, biotechnology students, pre-medical and pre-health students, microbiology students, and undergraduate laboratory science students. It is especially useful for students preparing for a practical or written laboratory final covering quantitative calculations, experimental design, microscopy, fluorescence imaging, cell viability, cryopreservation, mitochondrial assays, protein quantification, and electrophoresis. The uploaded document identifies BIOL 225 as the course code but does not state a university or college, so University Not Specified is used rather than assigning an unsupported institution. 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