SMRTbell libraries generally start at 10kb and go up in size from there. For effective libraries, fragment sizes must be 5-10kb larger than the desired length of the read. This requires a number of size-selection steps, which require repair steps. Because there are numerous washes and clean-ups, a significant amount of DNA is lost by the end of the process. For these libraries to be effective, we need to start with 10-20ug of DNA. For some organisms, this amount of DNA may not be realistic, but we can suggest other options (Whole Genome Amplification for example) that are not ideal, but may be a good compromise.
Optical Mapping is a much different approach than sequencing. For this approach very long (>200kb) fragments of DNA are enzymatically nicked, and the nicked sites are labeled. This requires a very time-intensive extraction and nicking/labeling process. High quality DNA is required, and so we would prefer to do the extractions here. If not, submitted DNA will need to meet very strict quality metrics.