Troubleshooting guide

Introduction

This trouble-shooting guide has been prepared by the technical staff of Biochemical Diagnostics, Inc. based on our own experience and the comments of those customers who have responded to our surveys. Our customers have reported very few technical problems when using our complete reagent kits, however, nobody is perfect and occasional problems do occur. In order to minimize startup problems, we ask that you read this guide and the package insert before attempting to set up our tests. If additional information is needed, we encourage you to contact us or leave an e-mail message and we will contact you. Included in this guide are some quality control recommendations for those of you who find it necessary to prepare some of your own reagents. While we discourage this practice, since performance cannot be guaranteed, we have included this information since it is our goal to satisfy every customer. Although our reagents are thoroughly tested for composition purity and performance in our own laboratory, there may be slight variations in the composition of different lot numbers of a particular reagent. Whenever possible, we encourage you to use complete reagent kits in order to obtain optimum performance. If possible, avoid using different lots of reagents or columns within a single run. When necessary, reagents of different lot numbers should be "pooled" and used as a homogeneous reagent. For best results, this rule should also be applied to reagents of the same lot number.


GENERAL PROBLEMS	CAUSE	POSSIBLE REMEDY

1. Floating Cotton Filter (Applies only to Steroid Columns)	Shipment	Before starting the run make sure that upper cotton plug is properly placed.

2. Column Flow Rates Vary	(a) Air trapped in the cotton or resin bed.	( a) Apply pressure by flow inducer or heel of your hand to remove the trapped air (indicated by bubbles coming out from the bottom). Note: Except for aspiration all the steps in the procedures are carried out by gravity flow. Flow inducing is done to remove the trapped air in order to get optimum flow rates.
	b) Layer of sediment on cotton plug	(b) Remove the upper cotton filter (Applies only to Steroid Columns) after urine adsorption in case of flow rate problem. If the urine flow rate is a problem (Ketogenic in particular), avoid pouring the heavy precipitate onto the column by carefully decanting the treated urine. A preliminary centrifugation step may be employed.
	(c) Use of wrong column	(c) Check the catalog number and label description.

3. Erratic Standards and Controls	a) Improper aspiration	(a) Make sure that the aspiration guidelines contained in the package inserts are carefully followed. Leftover sample, wash solution, etc., may change the elution solvent composition and will often create unpredictable side products. Check for aspiration by placing hand on top of reservoir. A moderate to strong pull should be felt.
	b) Improper mixing	(b) If a vortex mixer is used, make sure the two layers are thoroughly mixed and agitated. Alternatively an efficient extraction can be carried out by using a mechanical mixer or by manually shaking the tubes taped within a rack.
	c) Inaccurate pipetting	(c) Pipettes should be checked routinely for accuracy.
	d) Spectrophotometer	(d) The spectrophotometer should be calibrated and checked periodically.

4. Contamination of Glassware and Reagent	Acetone and other ketones, ammonia, carbonate and other interfering compounds	( a)The glassware should be cleaned and rinsed thoroughly (rinse with deionized or distilled water).
		(b) Avoid airborne contamination while test is carried out (especially at the time of aspiration).

5. Low Recovery of Standards and Controls	7% Column Activator wash is skipped	Make sure that 7% Column Activator wash (Applies only to Steroid Columns) is carried out prior to urine adsorption. (This wash optimizes the recovery and removes any adsorbed contaminant.)

6. Low Control Value	Decomposition	Look for the expiration date before use. If not stored at the recommended temperature the control may decompose.

7. Pigmented Eluates	a) Poor aspiration	a) A good aspiration is essential to the procedure. Interfering chromogens may remain in unremoved washing solution and subsequently be eluted. (See 3A for more details)
	b) Sample decomposition due to improper storage or contaminated with blood or fecal matter	b) Consult requesting physician and try to obtain a fresh uncontaminated sample.