A microcentrifuge performs centrifugation of small sample tubes, as used to concentrate biological cells and separate debris in the PV92 teaching experiment.

A scientist who investigates biological systems using physical methods and models. A biophysicist may connect single-molecule measurements with molecular mechanisms or use collective physical behavior to explain tissue organization.

Online text: qualifications.pearson.com/content/dam/pdf/A%20Level/biology-b/2015/teaching-and-learning-materials/AS-and-A-level-Biology-B-Core-Practical-4---Pollen-tube-growth-%28Student%2C-Teacher%2C-Technician-Worksheets%29.pdf

Seven-page teacher, student and technician worksheets in EDEXCEL Biology B Teacher Resource Pack 1, issued by Pearson Education Ltd. The printed copyright is 2015; no separate publication or revision date or personal byline is established. The teacher notes credit adaptation from several protocols including SAPS.

Cited passages: Teacher sheet, printed pp. 1–2 (PDF pp. 1–2), steps 3–8 and answer 1; Technician sheet, printed p. 1 (PDF p. 6), equipment and plant materials. Each sheet restarts its printed pagination.

Online text: practicalbiology.org/cells-to-systems/reproductive-systems/observing-the-growth-of-pollen-tubes

Published educational practical on Practical Biology, a Royal Society of Biology site. No personal byline or publication date is stated. September 2009 is a health and safety check; October 2011 is the access date of a linked website. Neither establishes publication.

Cited passages: Technical note 3; Teaching notes, male gametophyte, tube shape and the steps between pollen germination and seed formation.

By Harry Alfred Borthwick, Sterling Brown Hendricks, Marion W. Parker, Eben H. Toole, Vivian Kearns Toole.

Published in Proceedings of the National Academy of Sciences 38(8), pp. 662–666, August 1952. The communicated date, 7 June 1952, is a manuscript date.^[ref]

Online text: www.pnas.org/doi/pdf/10.1073/pnas.38.8.662

Cited passages: pp. 662–663: wet blotters, covered dishes, darkness, 20 °C and a two-prism glass spectrograph; p. 664: seven lots of 200 seeds, 16-hour dark imbibition, one-minute red and four-minute far-red exposures, and a two-day endpoint; p. 665, Table 1: qualitative red/far-red reversal and incomplete suppression; p. 663: pigment identification explicitly deferred.

By William E. Finch-Savage, Gerhard Leubner-Metzger.

Published in New Phytologist 171(3), pp. 501–523; first published online 14 July 2006.^[ref]

Online text: doi.org/10.1111/j.1469-8137.2006.01787.x

Cited passages: Summary, p. 501; §II.1 Seed structure and seed germination, p. 502; §II.2 Definition of seed dormancy, p. 502.

Online text: learn.k20center.ou.edu/lesson/215/Cell%20Respiration%20Lab.pdf?rev=16999

University of Oklahoma K20 Center educational laboratory handout adapted from the 2001 AP Biology Lab Manual. The associated lesson was published on 8 November 2022; that is not an established publication date for this undated attachment. Its tables are blank.

Cited passages: Cell Respiration, K20 Center handout adapted from AP Biology Lab Manual, pp. 3–4, procedure 1–16: preparation, equilibration and readings; Cell Respiration, pp. 1, 3–4 and 6: living dormant seeds, position/leaks, corrected differences and slope.

By Conly L. Rieder, Richard W. Cole, Alexey Khodjakov, Greenfield Sluder.

Online text: doi.org/10.1083/jcb.130.4.941

Experimental article published on 15 August 1995 in Journal of Cell Biology 130(4), pp. 941–948. The full author PDF was inspected at the separately linked copy.

Inspected PDF copy: pdfs.semanticscholar.org/d175/879a4000a67510e16d637c2cadea97250148.pdf

Cited passages: pp. 941–942, Abstract and Materials and Methods: Cell Culture; Laser Microsurgery and Video-enhanced Light Microscopy; pp. 943–947, arm-cutting control, Table I, Figures 1, 5 and 6; destruction of the last unattached kinetochore and correlative electron microscopy.

By Martha Hotz Vitaterna, Joseph S. Takahashi, Fred W. Turek.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC6707128/

Authored review published in 2001 in Alcohol Research & Health 25(2), pp. 85–93. The actually inspected PDF copy is linked below; the publisher record is hosted by PubMed Central.

Inspected PDF copy: pdfs.semanticscholar.org/d20b/6b8b6d0690851834d1164812ab7d99acb5ee.pdf

Cited passages: Vitaterna, Takahashi and Turek (2001), Overview of Circadian Rhythms, pp. 85–86, Biological Rhythms and Basic Properties of Circadian Rhythms; p. 92, glossary entries Entrainment, Free running and Masking; pp. 86–87, Figure 1A; p. 92, Free running; pp. 86–87, synchronization to external cues; p. 92, Entrainment and Zeitgeber.

By Martha Hotz Vitaterna, David P. King, Anne-Marie Chang, Jon M. Kornhauser, Phillip L. Lowrey, J. David McDonald, William F. Dove, Lawrence H. Pinto, Fred W. Turek, Joseph S. Takahashi.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC3839659/

Experimental article published on 29 April 1994 in Science 264(5159), pp. 719–725. The 2013 PMC availability date is distinct from journal publication.

Cited passages: Figure 2A–C; Table 2 and discussion of activity counts and loss of rhythmicity; References and Notes 10 and 14; Vitaterna and others (1994), Mutagenesis and Mapping of a Mouse Gene, Clock, Essential for Circadian Behavior, Figure 1 and References and Notes 6–10.

Online text: documents.thermofisher.com/TFS-Assets/BID/Handbooks/protein-preparation-handbook.pdf

Manufacturer scientific handbook issued by Thermo Fisher Scientific. The printed copyright range is 2016–2018; the document code does not establish its publication year. Figure 9A measures salt removal through conductivity, while Figure 8 measures protein retention separately; neither test alone establishes preserved enzymatic function.

Cited passages: Protein Preparation Handbook, printed p. 11, Figure 8 and caption: membrane series, preparation, duration, temperature and protein assay; the separately plotted vitamin B12 uses a different optical readout; Protein Preparation Handbook, printed p. 11, Figure 9A and caption: sample preparation, 10K membrane, baths, conductivity and conventional-dialysis reference.

Online text: documents.thermofisher.com/TFS-Assets/LSG/brochures/TR0020-Dialysis-overview.pdf

Manufacturer scientific technical note issued by Pierce Biotechnology, with copyright 2008 Thermo Fisher Scientific. Neither first publication nor revision date is established. The guidance describes membrane retention conventions and limitations, rather than guaranteeing recovery for every sample.

Cited passages: Dialysis: an overview, Tech Tip 20, p. 1, Dialysis is Diffusion Through a Semi-Permeable Membrane; Tech Tip 20, p. 1, Factors Affecting Dialysis Rate: MWCO definition and globular reference molecules; Tech Tip 20, p. 2, Other Factors in Dialysis: water transport, volume change and nonspecific membrane binding; Tech Tip 20, pp. 1-2, renewed gradients and Other Factors in Dialysis.

By P. R. Mueller, T. R. Coleman, Akiko Kumagai, William G. Dunphy.

Published in Science.

Online text: pubmed.ncbi.nlm.nih.gov/7569953/

Cited passages: Mueller, Coleman, Kumagai and Dunphy (1995), abstract: Xenopus clone, both inhibitory sites and immunodepletion result.

By Clare McGowan, Paul Russell.

Published in The EMBO Journal.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC413177/

Cited passages: McGowan and Russell (1993), abstract: purified human Wee1, Tyr15 specificity, no detectable Thr14 phosphorylation, and Lys114 mutant control.

By Richard W. Deibler, Marc W. Kirschner.

Published in Molecular Cell.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC2882237/

Cited passages: Deibler and Kirschner (2010), Experimental Procedures, “Tissue Culture, Flow Cytomtery, and Somatic Cell Extract Preparation”; Figure 2A; Deibler and Kirschner (2010), “H1 Kinase Assays”; Results, “A Three-Stage Activation Profile of CDK1 by Cyclin B”, reported Figure S2A inhibitor result; Figure 2B; Results, “Establishing a Somatic Cell Extract System for Mitotic Entry”; “A Three-Stage Activation Profile of CDK1 by Cyclin B”.

By M. J. Solomon, T. Lee, Marc W. Kirschner.

Published in Molecular Biology of the Cell.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC275499/

Cited passages: Solomon, Lee and Kirschner (1992), abstract: cyclin-binding triple mutant and activating phosphorylation of the kinase-inactive K33R mutant; Solomon, Lee and Kirschner (1992), abstract: mapped Xenopus Thr14/Tyr15, loss of activation with Thr161→Ala, and cyclin binding by the triple mutant.

By Colin W. Taylor, Stephen C. Tovey.

Publisher: Cold Spring Harbor Laboratory Press.

Published in Cold Spring Harbor Perspectives in Biology.

Online text: pmc.ncbi.nlm.nih.gov/articles/PMC2982166/

Cited passages: Taylor and Tovey, IP3 Receptors: Toward Understanding Their Activation, Abstract; regulation by cytosolic Ca2+ and Structural Determinants of IP3R Activation: three subtypes and tetrameric assemblies.

By H. Streb, E. Bayerdörffer, W. Haase, R. F. Irvine, Irene Schulz-Hofer.

Publisher: Springer.

Published in The Journal of Membrane Biology.

Online text: pubmed.ncbi.nlm.nih.gov/6334162/

Cited passages: Streb, Bayerdörffer, Haase, Irvine and Schulz, Effect of inositol-1,4,5-trisphosphate on isolated subcellular fractions of rat pancreas (1984), abstract: preparation, separation methods, protein-normalized release and marker correlations.

By Donal A. Walsh, John P. Perkins, Edwin G. Krebs.

Published in Journal of Biological Chemistry 243(13), 3763-3765.

Online text: www.researchgate.net/publication/18867934_An_Adenosine_3%275%27-Monophosphate-dependant_Protein_Kinase_from_Rabbit_Skeletal_Muscle

Cited passages: Walsh, Perkins and Krebs, 1968, printed p. 3763 Summary and introductory paragraphs: cAMP-dependent kinase and phosphorylase kinase activation.

By P. C. Sternweis, J. K. Northup, M. D. Smigel, Alfred G. Gilman.

Published in Journal of Biological Chemistry 256(22), 11517-11526.

Online text: pubmed.ncbi.nlm.nih.gov/6271754/

Cited passages: Abstract, properties 2-4: purified guanine-nucleotide regulatory component reconstitutes hormone-stimulated adenylyl cyclase.