Automated zebrafish chorion removal and single embryo placement: optimizing throughput of zebrafish developmental toxicity screens

J Lab Autom. 2012 Feb;17(1):66-74. doi: 10.1177/2211068211432197.


The potential of the developing zebrafish model for toxicology and drug discovery is limited by inefficient approaches to manipulating and chemically exposing zebrafish embryos-namely, manual placement of embryos into 96- or 384-well plates and exposure of embryos while still in the chorion, a barrier of poorly characterized permeability enclosing the developing embryo. We report the automated dechorionation of 1600 embryos at once at 4 h postfertilization (hpf) and placement of the dechorionated embryos into 96-well plates for exposure by 6 hpf. The process removed ≥95% of the embryos from their chorions with 2% embryo mortality by 24 hpf, and 2% of the embryos malformed at 120 hpf. The robotic embryo placement allocated 6-hpf embryos to 94.7% ± 4.2% of the wells in multiple 96-well trials. The rate of embryo mortality was 2.8% (43 of 1536) from robotic handling, the rate of missed wells was 1.2% (18 of 1536), and the frequency of multipicks was <0.1%. Embryo malformations observed at 24 hpf occurred nearly twice as frequently from robotic handling (16 of 864; 1.9%) as from manual pipetting (9 of 864; 1%). There was no statistical difference between the success of performing the embryo placement robotically or manually.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Automation, Laboratory*
  • Chorion / metabolism*
  • Drug Discovery*
  • Drug Evaluation, Preclinical / instrumentation
  • Drug Evaluation, Preclinical / methods
  • Embryonic Development / drug effects
  • High-Throughput Screening Assays*
  • Robotics / trends
  • Single Embryo Transfer / instrumentation*
  • Single Embryo Transfer / methods
  • Toxicity Tests*
  • Zebrafish