Low power laser induced fluorescence of dihematoporphyrin ether (DHE, photofrin 2) is used to detect cancer. The goal was to determine the effect of low power argon laser light and DHE on C-1300 murine neuroblastoma cells (MNB, NB41A3). The study groups were as follows: Control, untreated cells (C), DHE only at concentrations of 1 (D1) and 5 (D5) µg/ml, Argon laser 2 light only at exposure times of 1 minute (1.8 J/cm2 , L1) 2 and 5 minutes (9.0 J/cm2 , L5), combined treatment of Light at 1, 5 minutes, and DHE at 1, 5 µg/ml.

Nine replicates were performed following incubation of cells in either 1.0 µg DHE/ml or 5 µg DHE/ml for two hours. The Cooper Lasersonics lexel model 150 argon laser was used.

Cell growth was measured by counting cells, and cell viability by trypan blue exclusion was determined post treatment at 1, 24, 96, and 144 hours. Catechol amine analysis of cell supernatant was performed by Amersham Radioenzymatic Cat-A-KitR assay. The results were: cell numbers decreased immediately and remained low for 9 days in the groups treated with Light for 1 and 5 minutes and 5.0 µg DHE/ml, and in Light 5 minutes with 1.0 µg DHE/ml group as compared with all other treatment groups. Cell viability followed the same trend with the L5 group, L1 at 5 µg DHE/ml, and L5 group at 1 µg DHE/ml as compared with group C. Cell morphology was altered in these groups. Cells changed shape becoming rounded, contained vacuoles, and pyknotic inclusions.

It was concluded that light alone with 5 minutes exposure kills cells, but light alone with 1 minute expo sure has no effect on C1300 MNB cells. However, cells were damaged and killed, affected in groups L1D5, L5D1, and L5D5. Catecholamine concentration was below the detection limit of the assay for most samples. Therefore, no interpretation can be made about using catecholamines as a marker of cell status.

Low energy argon laser light at the power density of 30 mW/cm2 and DHE concentrations of 1 and 5 µg/ml that is used for detection of cancer causes changes in cell morphology, number, and viability in this in vitro model.

Library of Congress Subject Headings

Photochemotherapy; Neuroblastoma--Treatment; Argon lasers--Therapeutic use

Publication Date


Document Type


Student Type



R. Bayer

Advisor/Committee Member

J. R. Hinshaw

Advisor/Committee Member

N. Kubasik


Physical copy available from RIT's Wallace Library at RC271.P43 R636 1988


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