title: Use of a laser diffraction particle sizer for the measurement of mean diameter of multicellular tumor spheroids.
abstract: Increasing use is being made of tumor cell lines cultured as cell aggregates (generally referred to as multicellular spheroids) in in vitro radiosensitivity and/or chemosensitivity tests. Conventional procedures for the determination of mean spheroid diameters for the construction of growth delay curves employ a microscope-image analyzer. However, this approach can prove excessively time consuming when large numbers of samples have to be measured. We have, therefore, been exploring the use of a Laser Diffraction Particle Sizer, the Malvern 2600 long bench model, for the measurement of mean spheroid diameter and size distribution. We report here a direct comparison between measurements carried out by the instrument and under the microscope. Also a comparison of growth curves for six cell lines constructed from measurements by the microscope and by the instrument. A number of factors that might affect the accuracy of spheroid diameter measurement by the instrument have been investigated: The effect of stirring to maintain the spheroids in suspension during measurement. Sampling error due to removal of a series of spheroid samples from culture flasks for measurement. Optimum numbers of scans to be carried out by the instrument to reach a constant value for mean diameter, and minimum SE of the mean.
authors: University Department of Radiotherapy, Cookridge Hospital, Leeds, United Kingdom.
authors: C D
authors: CD
authors: Boothby
authors: J
authors: J
authors: Daniel
authors: S
authors: S
authors: Adam
authors: J E
authors: JE
authors: Dyson
mesh_terms: D000818:Animals; D002460:Cell Line; D002469:Cell Separation / Q000295:instrumentation*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007834:Lasers; D008175:Lung Neoplasms / Q000473:pathology*; D010316:Particle Size; D014407:Tumor Cells, Cultured; D002583:Uterine Cervical Neoplasms / Q000473:pathology*