title: SPICE-NIRS microbeam: a focused vertical system for proton irradiation of a single cell for radiobiological research.
abstract: The Single Particle Irradiation system to Cell (SPICE) facility at the National Institute of Radiological Sciences (NIRS) is a focused vertical microbeam system designed to irradiate the nuclei of adhesive mammalian cells with a defined number of 3.4 MeV protons. The approximately 2-μm diameter proton beam is focused with a magnetic quadrupole triplet lens and traverses the cells contained in dishes from bottom to top. All procedures for irradiation, such as cell image capturing, cell recognition and position calculation, are automated. The most distinctive characteristic of the system is its stability and high throughput; i.e. 3000 cells in a 5 mm × 5 mm area in a single dish can be routinely irradiated by the 2-μm beam within 15 min (the maximum irradiation speed is 400 cells/min). The number of protons can be set as low as one, at a precision measured by CR-39 detectors to be 99.0%. A variety of targeting modes such as fractional population targeting mode, multi-position targeting mode for nucleus irradiation and cytoplasm targeting mode are available. As an example of multi-position targeting irradiation of mammalian cells, five fluorescent spots in a cell nucleus were demonstrated using the γ-H2AX immune-staining technique. The SPICE performance modes described in this paper are in routine use. SPICE is a joint-use research facility of NIRS and its beam times are distributed for collaborative research.
authors.affiliation: Research Development and Support Center, National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba-shi 263-8555, Japan. tkonishi@nirs.go.jp
authors.forename: Teruaki
authors.initials: T
authors.lastname: Konishi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Oikawa
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Suya
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Maeda
authors.forename: Alisa
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Naoko
authors.initials: N
authors.lastname: Shiomi
authors.forename: Kumiko
authors.initials: K
authors.lastname: Kodama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamano
authors.forename: Shino
authors.initials: S
authors.lastname: Homma-Takeda
authors.forename: Mayu
authors.initials: M
authors.lastname: Isono
authors.forename: Kotaro
authors.initials: K
authors.lastname: Hieda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Uchihori
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shirakawa
mesh_terms: D024201:Bystander Effect / Q000528:radiation effects; D002467:Cell Nucleus / Q000528:radiation effects*; D003593:Cytoplasm / Q000528:radiation effects; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D006657:Histones / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence; D010315:Particle Accelerators / Q000295:instrumentation*; D011092:Polyethylene Glycols / Q000737:chemistry; D011522:Protons; D011829:Radiation Dosage; D011853:Radiobiology / Q000295:instrumentation*
chemical_list: C468783:H2AX protein, human; D006657:Histones; D011522:Protons; C028827:CR 39; D011092:Polyethylene Glycols
keywords: bystander effect; low dose effect; microbeam; proton; single hit; target irradiation; vertical beam