#qpcr-efficiency-calculator { max-width: 600px; margin: 20px auto; padding: 15px; background: #fff; border-radius: 5px; box-shadow: 0 1px 3px rgba(0,0,0,0.1); font-family: -apple-system, BlinkMacSystemFont, ‘Arial’, sans-serif; color: #333; box-sizing: border-box; } h2 { text-align: center; margin: 0 0 15px; font-size: 1.4rem; line-height: 1.2; color: #333; } p { text-align: center; color: #666; font-size: 14px; margin-bottom: 15px; } .form-group { margin-bottom: 15px; position: relative; } label { display: block; margin-bottom: 5px; font-size: 0.9rem; font-weight: 600; } input[type=”number”] { width: 100%; padding: 8px; border: 1px solid #ddd; border-radius: 3px; font-size: 0.9rem; box-sizing: border-box; } input:focus { border-color: #0073aa; outline: none; } .tooltip { position: relative; display: inline-block; margin-left: 5px; } .tooltip .tooltip-text { visibility: hidden; width: 180px; background: #333; color: #fff; text-align: center; border-radius: 3px; padding: 5px; position: absolute; z-index: 10; bottom: 125%; left: 50%; transform: translateX(-50%); opacity: 0; transition: opacity 0.3s; font-size: 0.75rem; } .tooltip:hover .tooltip-text { visibility: visible; opacity: 1; } .button-group { display: flex; gap: 10px; justify-content: center; margin-top: 15px; } button { padding: 8px 16px; border: none; border-radius: 3px; cursor: pointer; font-size: 0.9rem; background: #0073aa; color: #fff; } button:hover { background: #005177; } #reset-btn { background: #6c757d; } #reset-btn:hover { background: #5a6268; } #copy-btn { background: #28a745; } #copy-btn:hover { background: #218838; } #result { margin-top: 15px; padding: 10px; border-radius: 3px; font-size: 0.9rem; line-height: 1.4; min-height: 20px; } #result.success { background: #e6f4ea; border: 1px solid #28a745; } #result.error { background: #f8d7da; border: 1px solid #dc3545; } #standard-curve { display: block; margin: 10px auto; max-width: 100%; border: 1px solid #ddd; } noscript { display: block; color: #dc3545; text-align: center; margin-top: 10px; font-size: 0.9rem; } @media (max-width: 600px) { #qpcr-efficiency-calculator { margin: 10px; padding: 10px; } h2 { font-size: 1.2rem; } .button-group { flex-direction: column; } button { width: 100%; } }

Enhanced qPCR Efficiency Calculator

Calculate qPCR efficiency with a standard curve visualization.

JavaScript is disabled. Please enable it to use the calculator. (function() { if (!document.getElementById(‘qpcr-efficiency-calculator’)) return; const form = document.getElementById(‘calc-form’); const slopeInput = document.getElementById(‘slope’); const ctValueInput = document.getElementById(‘ct-value’); const resultDiv = document.getElementById(‘result’); const canvas = document.getElementById(‘standard-curve’); const ctx = canvas.getContext(‘2d’); function drawStandardCurve(slope, intercept = 20) { canvas.style.display = ‘block’; ctx.clearRect(0, 0, canvas.width, canvas.height); const padding = 40; const xMax = canvas.width – padding * 2; const yMax = canvas.height – padding * 2; const logQuantities = [0, 1, 2, 3, 4, 5]; const ctValues = logQuantities.map(x => intercept + slope * x); ctx.beginPath(); ctx.strokeStyle = ‘#0073aa’; ctx.lineWidth = 2; ctx.moveTo(padding, canvas.height – padding); ctx.lineTo(canvas.width – padding, canvas.height – padding); ctx.moveTo(padding, padding); ctx.lineTo(padding, canvas.height – padding); ctx.stroke(); ctx.font = ’12px Arial’; ctx.fillStyle = ‘#333’; ctx.textAlign = ‘center’; ctx.fillText(‘Log(Quantity)’, canvas.width / 2, canvas.height – 10); ctx.save(); ctx.translate(10, canvas.height / 2); ctx.rotate(-Math.PI / 2); ctx.fillText(‘Ct Value’, 0, 0); ctx.restore(); const xScale = xMax / 5; const yScale = yMax / (Math.max(…ctValues) – Math.min(…ctValues)); const yMin = Math.min(…ctValues); logQuantities.forEach((x, i) => { ctx.fillText(x.toString(), padding + x * xScale, canvas.height – padding + 15); const y = canvas.height – padding – (ctValues[i] – yMin) * yScale; if (i === 0) { ctx.beginPath(); ctx.moveTo(padding + x * xScale, y); } else { ctx.lineTo(padding + x * xScale, y); } }); ctx.strokeStyle = ‘#28a745’; ctx.stroke(); ctValues.forEach((ct, i) => { const y = canvas.height – padding – (ct – yMin) * yScale; ctx.beginPath(); ctx.arc(padding + i * xScale, y, 3, 0, 2 * Math.PI); ctx.fillStyle = ‘#28a745’; ctx.fill(); }); } function calculate() { resultDiv.className = ”; resultDiv.innerHTML = ”; canvas.style.display = ‘none’; try { const slope = parseFloat(slopeInput.value); const ctValue = parseFloat(ctValueInput.value) || null; if (isNaN(slope)) { throw new Error(‘Slope must be a number.’); } if (slope >= 0) { throw new Error(‘Slope must be negative (e.g., -3.32).’); } if (ctValue !== null && ctValue = 90 && efficiency <= 110) { interpretation = 'Acceptable efficiency (90–110%). Your qPCR assay is performing well.'; tips = 'Maintain current conditions for reliable quantification.'; } else if (efficiency < 90) { interpretation = 'Efficiency too low (110%). Possible assay issues.’; tips = ‘Investigate primer dimers, sample inhibitors, or dilution errors.’; } let quantityEstimate = ”; if (ctValue !== null) { const relativeQuantity = Math.pow(amplificationFactor, -ctValue); quantityEstimate = `
Estimated Relative Quantity: ${relativeQuantity.toExponential(2)} (based on Ct = ${ctValue})`; } drawStandardCurve(slope); resultDiv.innerHTML = ` qPCR Efficiency: ${efficiency.toFixed(2)}%
Amplification Factor: ${amplificationFactor.toFixed(3)}
Interpretation: ${interpretation}
Tips: ${tips} ${quantityEstimate}
`; resultDiv.className = ‘success’; document.getElementById(‘copy-btn’).addEventListener(‘click’, () => { const text = ` qPCR Efficiency Results Slope: ${slope} Efficiency: ${efficiency.toFixed(2)}% Amplification Factor: ${amplificationFactor.toFixed(3)} Interpretation: ${interpretation} Tips: ${tips} ${quantityEstimate ? `Estimated Relative Quantity: ${relativeQuantity.toExponential(2)} (Ct = ${ctValue})` : ”} `.trim(); navigator.clipboard.writeText(text).then(() => { alert(‘Results copied to clipboard!’); }); }); } catch (error) { resultDiv.innerHTML = `Error: ${error.message}`; resultDiv.className = ‘error’; } } function reset() { form.reset(); resultDiv.className = ”; resultDiv.innerHTML = ‘Enter the slope, then click “Calculate”.’; canvas.style.display = ‘none’; slopeInput.focus(); } document.getElementById(‘calculate-btn’).addEventListener(‘click’, calculate); document.getElementById(‘reset-btn’).addEventListener(‘click’, reset); form.addEventListener(‘keypress’, function(e) { if (e.key === ‘Enter’ && e.target.tagName !== ‘BUTTON’) { e.preventDefault(); calculate(); } }); })();