Lab Equipment FAQ: Sartorius Loops, Eline Pipette Manual, 700g Calibrator, and HPLC Columns

I'm the person who handles lab equipment orders and makes sure things don't break. In six years, I've personally made (and documented) 14 significant mistakes, totaling roughly $23,000 in wasted budget. That's why I keep a checklist. These are the questions we get the most.

What's the difference between a Sartorius chromatography sample loop and a Super Loop?

Short version: a sample loop is a fixed-volume tube you use to inject a precise sample amount. A Super Loop is a larger, reusable loop assembly that lets you load variable volumes without physically changing the loop. It's handy for preparative runs where you don't want to switch hardware every time the load volume changes.

The mistake I made in March 2023? I ordered 'Super Loops' thinking they were just bigger sample loops. They are. But I also missed that they need a specific fill procedure — you're not supposed to just push sample through at full HPLC pressure. I didn't read the manual (yeah, I know) and damaged the loop seals. That error cost roughly $850 in replacement parts plus a week of downtime.

So before you buy: check the volume range, pressure rating, and connector compatibility. According to Sartorius product documentation (sartorius.com), the loop's working pressure depends on the tubing material and fittings. Don't assume stainless steel is the same as PEEK. It isn't.

How do I find the Sartorius Eline electronic pipette manual?

You can download the PDF from Sartorius's website, but I'll save you the search: search for 'Sartorius Eline electronic pipette manual' and look for the PDF from sartorius.com. The manual is also usually packed in the pipette box. Yes, the paper one. I know nobody reads it.

Here's why you should. My first Eline error code happened in 2022. The pipette just stopped responding after a low-battery warning. I assumed it was dead. It wasn't. The manual said 'replace battery, confirm with self-test.' Ten minutes later, it worked. If I had thrown it away, that would have been a $700 mistake.

What else is in the manual? Setting the volume, switching from pipetting to dispensing, reverse pipetting, and calibration check instructions. Keep a printed copy in the lab. Also note: electronic pipettes use different logic than mechanical ones. You can't just twist the plunger until it clicks. There's an actual menu.

What can a 700g pressure gauge calibrator actually do for you?

A 700g pressure gauge calibrator gives you a portable reference to verify process gauges in your facility. The 'g' in the name is the model family designation, not 'grams.' You use it to compare what your process gauge reads against a known accurate reference. If the reading is off by more than your tolerance, you schedule a repair or recalibration.

Here's the thing I learned the hard way: a brand-new gauge can be wrong. In 2021, I skipped initial calibration because the gauge had a certificate. In the box. The certificate was for a different unit. Oops. That was a $200 gauge that almost got used in a process requiring ±0.5% accuracy. We caught it during a routine audit. The cost of the audit was nothing compared to the cost of a bad batch.

Use a 700g calibrator as a first-line check, not a substitute for accredited lab calibration. For ISO requirements, you still need traceability to NIST or equivalent. Check your procedure. According to our calibration logs, drift happens quickly when a gauge lives in high-vibration equipment.

How do I choose an HPLC column without making a $700 mistake?

Start with your sample. Polar or non-polar? Acidic or basic? Then look at particle size, pore size, and phase chemistry. A C18 column is a reasonable default for many small molecules, but it's not for everything. The mobile phase pH, buffer concentration, and flow rate all affect the column's lifetime.

My earliest HPLC lesson involved a colleague who blamed a 'dead column' because retention times were drifting. He replaced the column. The problem came back. The actual cause was a contaminated inline filter and an unstable mobile phase. The new column was trashed three weeks later. That cost more than I care to admit.

Before you replace a column: check the pressure. If pressure climbs gradually, look for blocked frits or salt precipitation. Run a blank gradient. Look at the plate count. According to most column care guides, if plate count drops by 50% or more, the column may be done. But if it's an old column, sometimes reversing the flow (with the manufacturer's permission) can fix a contaminated inlet. Read the test chromatogram that came with the column and compare.

How do I use an Eppendorf pipette correctly?

The same fundamentals apply to any piston pipette, including Sartorius models. Set the volume within the pipette's range, attach a proper tip, pre-wet it once or twice, hold the pipette vertically, and press the plunger to the first stop. Immerse the tip just below the surface, then release the plunger slowly to aspirate. Withdraw the tip. To dispense, press to the first stop, pause, then press to the second stop to blow out any remaining liquid. Touch the tip against the side of the vessel before pulling it away.

Why does pre-wetting matter? It humidifies the dead air inside the tip. If you skip it, evaporation changes the volume. The difference is small, but in a calibration lab, small matters.

I didn't fully understand this until our annual pipette check. One person's results were consistently low. They were using the same pipette and procedure. Except the procedure missed the pre-wet step. Once fixed, the numbers came in line. No new pipette needed.

And if you're using an Eppendorf, use Eppendorf tips or equivalent certified tips. Tips from unknown suppliers can leak tiny amounts of plasticizer into your sample. Not worth saving a few cents.

Is it ever smart to buy the cheapest lab equipment?

Not usually. But I'm not saying buy the most expensive either. I'm saying look at total cost. A cheap syringe filter that clogs and ruins a column costs way more than 20 cents. A questionable pressure gauge that fails an audit can pause production for a day.

Here's a comparison that changed how I think. We once ordered two sets of calibration weights. One set from a no-name vendor at 40% less. The other from a distributor with a traceable certificate. The no-name weights looked identical when they arrived. We sent them out for verification. Half failed. The cost of verification was almost as much as the savings. The traceable set passed on the first try.

That's the value-over-price lesson. The lowest quoted price doesn't include the hidden costs: re-testing, reordering, delays, or lost credibility. From my experience, the lowest quote has cost us more in 60% of cases. That's not an exact statistic, but it's a real pattern from our purchase logs.

Do you need a top-of-the-line HPLC column for every separation? No. Sometimes a standard C18 is enough. But buy from sources you can verify, and account for the cost of failure. That's the real math. Value over price. Every time.

What's the most common mistake when ordering Sartorius sample loops and Super Loops?

Assuming 'loop' means 'one size fits all.' I once told a supplier 'we need a Super Loop.' They heard 'sample loop.' The result was a 2 mL sample loop when we needed a 50 mL Super Loop. Same word family, completely different part. We caught it when the order arrived. No, we didn't read the packing slip before opening the box.

That's a communication failure. I said 'Super Loop.' They heard 'sample loop.' We both meant something different. Now my checklist says: include the volume, part number, and pressure rating in every order. If the part number isn't on the purchase order, the order doesn't get approved.

Also, check the fittings. Sartorius Super Loops come in different connection types. If your system uses 1/4-28 fittings and you order 1/8 inch compression, the loop won't fit. You don't find that out until you're mid-run. Always confirm the connection type with your chromatography system's manual. This sounds obvious, but I've made that exact mistake.