Questions before an editing-validation enquiry

The email says "please confirm our CRISPR" and names a gene. Nobody can price, primer, or interpret that sentence. Questions before an editing-validation enquiry are the missing fields that turn a wish into a specification. How the edit was supposed to arise is in how CRISPR-Cas9 editing works in research. What a returned sequence is allowed to prove is in checking whether a genome edit worked. A general habit for sourcing notes is in how to write a laboratory sourcing enquiry. This page is the editing-specific list.

Cell type, strain, and whether you cloned

Write the organism and the line or strain in the words your freezer uses, plus a source if the name is ambiguous. A pooled well and a single-cell clone are different analytical objects. A clone can hide an unedited extra copy if the parent was aneuploid. A pool is a mixture by default. Say which one is in the tube.

If the cells are primary, name the tissue origin at the level your approval already uses, without turning the enquiry into a clinical history. If they are bacterial, give the strain genotype that matters for restriction or recombination. The person designing primers needs to know what genome they are allowed to assume.

Delivery class

Plasmid, messenger RNA, ribonucleoprotein, and viral vector leave different traces in the sample and different expectations about how long the nuclease was present. A plasmid can still be in the cells and can contaminate a PCR if primers are careless. A ribonucleoprotein will not show up as a resistance marker. State the class you used. You do not need a microlitre table. You do need the class, because it changes which negative control makes sense and which contaminant to fear.

If delivery failed, validation sequencing of an unedited locus is still a legitimate result, but only if you do not describe it later as a knockout. Note whether a known-cutting control was included and what it did.

Guide sequences and the enzyme

Paste the spacer 5-prime to 3-prime, and name the enzyme, including the species or the variant. SpCas9 and SaCas9 do not share a motif. A spacer without the enzyme cannot be checked against the locus. If you used a two-RNA format, say so, and include both sequences or the catalogue class of the scaffold.

The full record that lets someone else reorder is in recording guides so an experiment can be repeated. The enquiry can be shorter, but it cannot be a nickname like "guide 3" unless the spacer is attached.

If several guides were used in one pool, list them. A single trace from a multi-guide pool will look mixed for a boring reason.

Genome build and locus

Coordinates without a build are incomplete. Copy the assembly name from the browser you used, such as Ensembl or the UCSC Genome Browser. Add chromosome or accession, start and end of the window you care about, and the gene symbol only as a convenience.

Mark where the cut was intended to fall inside that window. If a donor was used, include the donor sequence and say which bases should differ from the parent. Without that, an analyst can report "difference from reference" and still miss whether the difference is the repair you wanted or a scar.

Parental sequence matters when the line is not the reference. If you already know a SNP removes a primer site or a motif, write it down. Discovering it after the primers fail wastes the shipment.

Sample count and names

State how many tubes, how they are labelled, and which ones are controls: parent, no-template if you prepared amplicons yourself, non-targeting, known cutter. A number alone ("n = 24") without a map becomes twenty-four anonymous files. The map is part of the scientific content.

Say whether DNA is already extracted or whether cells or colonies are being sent, and follow the receiver's conditions for what they can accept. Do not ship material your approval does not allow to leave the building. A quotation cannot repair that.

The readout you actually want

Choose, or describe, the sentence the data must support. "Is this clone homozygous for a frameshift at this window" is a different request from "what fraction of reads in this pool carry any indel" and different again from "do these three nominated off-target sites show scars". On-target amplicon sequencing does not answer the third sentence. Asking for it without naming the extra loci guarantees an overclaimed report.

Sanger traces suit many clonal checks. Counted reads suit pools and low-frequency questions. The method-class background is the Illumina overview of next-generation sequencing, which is not a commitment that a particular instrument will be used. File types you should ask to receive are set out in what sequence data to request after an edit. Put those file types in the enquiry if you need them. A PDF-only deliverable will disappoint you later.

Gaps that send the enquiry back

A gene name with no coordinates comes back. A spacer written 3-prime to 5-prime without saying so comes back as the wrong site, or as no site. A request for "off-target free" with no list and no method comes back narrowed or refused as a claim. A sample count that does not match the tubes in the parcel comes back as an identity problem. Fix these before shipping. They are cheaper in email than in a rerun.

If the scientific question is still "did the Surveyor gel miss a homozygous edit", say that. The sequencing request is then a comparison of the clone with the parent, not a fishing trip. The branch logic for the gel is in troubleshooting no cutting on a surveyor assay.

Approvals stay outside the email

An enquiry about research validation does not file biosafety or ethics paperwork. Those decisions remain with your institution, including, in India, whatever institutional biosafety committee and recombinant-DNA rules apply to shipping engineered material. Do not ask a supplier to invent that status. If the work involves human embryos or a germline claim, do not send it as a routine validation. This page gives no method for that work. The boundary is discussed in ethics and approvals are outside a reagent quote.

Heat and couriers still belong in the practical note. Label tubes so a warm van does not leave you with barcodes and no names. Ask for files, not only paper, because a printed trace that sits in a humid inbox is a poor archive. If a power cut interrupts a file transfer, confirm the files are complete before you release the last aliquot of a precious clone.

Where to send the filled list

Use the quote request and attach the six fields. The CRISPR validation sequencing enquiry reference is the discussion prompt for that specification. It is an independent method reference. Ask whether a quotation is possible. Primers, polymerases, and clean-up classes, if you still need to prepare the amplicon, are browsed in the molecular biology catalogue. The molecular biology pathway is the surrounding research context. None of these pages is a clinical test menu.